diff --git a/app/ui/legacy/src/main/java/com/fsck/k9/ui/ThemeExtensions.kt b/app/ui/legacy/src/main/java/com/fsck/k9/ui/ThemeExtensions.kt
index d8aa489e0..51c73e2d0 100644
--- a/app/ui/legacy/src/main/java/com/fsck/k9/ui/ThemeExtensions.kt
+++ b/app/ui/legacy/src/main/java/com/fsck/k9/ui/ThemeExtensions.kt
@@ -1,6 +1,7 @@
 package com.fsck.k9.ui
 
 import android.content.res.Resources.Theme
+import android.graphics.Color
 import android.graphics.drawable.Drawable
 import android.util.TypedValue
 
@@ -15,6 +16,32 @@ fun Theme.resolveColorAttribute(attrId: Int): Int {
     return typedValue.data
 }
 
+fun Theme.resolveColorAttribute(colorAttrId: Int, alphaFractionAttrId: Int, backgroundColorAttrId: Int): Int {
+    val typedValue = TypedValue()
+
+    if (!resolveAttribute(colorAttrId, typedValue, true)) {
+        error("Couldn't resolve attribute ($colorAttrId)")
+    }
+    val color = typedValue.data
+
+    if (!resolveAttribute(alphaFractionAttrId, typedValue, true)) {
+        error("Couldn't resolve attribute ($alphaFractionAttrId)")
+    }
+    val colorPercentage = TypedValue.complexToFloat(typedValue.data)
+    val backgroundPercentage = 1 - colorPercentage
+
+    if (!resolveAttribute(backgroundColorAttrId, typedValue, true)) {
+        error("Couldn't resolve attribute ($colorAttrId)")
+    }
+    val backgroundColor = typedValue.data
+
+    val red = colorPercentage * Color.red(color) + backgroundPercentage * Color.red(backgroundColor)
+    val green = colorPercentage * Color.green(color) + backgroundPercentage * Color.green(backgroundColor)
+    val blue = colorPercentage * Color.blue(color) + backgroundPercentage * Color.blue(backgroundColor)
+
+    return Color.rgb(red.toInt(), green.toInt(), blue.toInt())
+}
+
 fun Theme.resolveDrawableAttribute(attrId: Int): Drawable {
     val typedValue = TypedValue()
 
diff --git a/app/ui/legacy/src/main/java/com/fsck/k9/ui/messagelist/MessageListAdapter.kt b/app/ui/legacy/src/main/java/com/fsck/k9/ui/messagelist/MessageListAdapter.kt
index b58281a03..18c937c28 100644
--- a/app/ui/legacy/src/main/java/com/fsck/k9/ui/messagelist/MessageListAdapter.kt
+++ b/app/ui/legacy/src/main/java/com/fsck/k9/ui/messagelist/MessageListAdapter.kt
@@ -51,8 +51,16 @@ class MessageListAdapter internal constructor(
     private val answeredIcon: Drawable = theme.resolveDrawableAttribute(R.attr.messageListAnswered)
     private val forwardedAnsweredIcon: Drawable = theme.resolveDrawableAttribute(R.attr.messageListAnsweredForwarded)
     private val previewTextColor: Int = theme.resolveColorAttribute(R.attr.messageListPreviewTextColor)
-    private val activeItemBackgroundColor: Int = theme.resolveColorAttribute(R.attr.messageListActiveItemBackgroundColor)
-    private val selectedItemBackgroundColor: Int = theme.resolveColorAttribute(R.attr.messageListSelectedBackgroundColor)
+    private val activeItemBackgroundColor: Int = theme.resolveColorAttribute(
+        colorAttrId = R.attr.messageListActiveItemBackgroundColor,
+        alphaFractionAttrId = R.attr.messageListActiveItemBackgroundAlphaFraction,
+        backgroundColorAttrId = R.attr.messageListActiveItemBackgroundAlphaBackground
+    )
+    private val selectedItemBackgroundColor: Int = theme.resolveColorAttribute(
+        colorAttrId = R.attr.messageListSelectedBackgroundColor,
+        alphaFractionAttrId = R.attr.messageListSelectedBackgroundAlphaFraction,
+        backgroundColorAttrId = R.attr.messageListSelectedBackgroundAlphaBackground
+    )
     private val regularItemBackgroundColor: Int = theme.resolveColorAttribute(R.attr.messageListRegularItemBackgroundColor)
     private val readItemBackgroundColor: Int = theme.resolveColorAttribute(R.attr.messageListReadItemBackgroundColor)
     private val unreadItemBackgroundColor: Int = theme.resolveColorAttribute(R.attr.messageListUnreadItemBackgroundColor)
diff --git a/app/ui/legacy/src/main/res/drawable/ic_check_circle_large.xml b/app/ui/legacy/src/main/res/drawable/ic_check_circle_large.xml
index 6483898ca..52c9bcc0d 100644
--- a/app/ui/legacy/src/main/res/drawable/ic_check_circle_large.xml
+++ b/app/ui/legacy/src/main/res/drawable/ic_check_circle_large.xml
@@ -6,7 +6,7 @@
   <path
       android:pathData="M20,20m-20,0a20,20 0,1 1,40 0a20,20 0,1 1,-40 0"
       android:strokeWidth="1"
-      android:fillColor="#1976d2"
+      android:fillColor="?attr/messageListSelectedCheckMarkColor"
       android:strokeColor="#00000000"/>
   <path
       android:pathData="m16.795,23.875 l-4.17,-4.17 -1.42,1.41 5.59,5.59 12,-12 -1.41,-1.41z"
diff --git a/app/ui/legacy/src/main/res/layout/message_list_fragment.xml b/app/ui/legacy/src/main/res/layout/message_list_fragment.xml
index 6e7996124..975566b9a 100644
--- a/app/ui/legacy/src/main/res/layout/message_list_fragment.xml
+++ b/app/ui/legacy/src/main/res/layout/message_list_fragment.xml
@@ -33,6 +33,9 @@
         android:layout_margin="@dimen/floatingActionButtonMargin"
         android:contentDescription="@string/compose_action"
         android:text="@string/compose_action"
-        app:icon="?attr/iconActionCompose" />
+        android:textColor="?attr/floatingActionButtonForegroundColor"
+        app:backgroundTint="?attr/floatingActionButtonBackgroundColor"
+        app:icon="?attr/iconActionCompose"
+        app:iconTint="?attr/floatingActionButtonForegroundColor" />
 
 </androidx.coordinatorlayout.widget.CoordinatorLayout>
diff --git a/app/ui/legacy/src/main/res/values/attrs.xml b/app/ui/legacy/src/main/res/values/attrs.xml
index 4c8f7d1c3..c17bff604 100644
--- a/app/ui/legacy/src/main/res/values/attrs.xml
+++ b/app/ui/legacy/src/main/res/values/attrs.xml
@@ -4,6 +4,8 @@
     <declare-styleable name="K9Styles">
         <attr name="toolbarColor" format="reference|color" />
         <attr name="bottomBarBackground" format="reference|color" />
+        <attr name="floatingActionButtonBackgroundColor" format="reference|color" />
+        <attr name="floatingActionButtonForegroundColor" format="reference|color" />
         <attr name="iconUnifiedInbox" format="reference" />
         <attr name="iconFolder" format="reference" />
         <attr name="iconFolderInbox" format="reference" />
@@ -65,13 +67,18 @@
         <attr name="textColorPrimaryRecipientDropdown" format="reference" />
         <attr name="textColorSecondaryRecipientDropdown" format="reference" />
         <attr name="backgroundColorChooseAccountHeader" format="color" />
+        <attr name="messageListSelectedCheckMarkColor" format="reference|color"/>
         <attr name="messageListSelectedBackgroundColor" format="reference|color"/>
+        <attr name="messageListSelectedBackgroundAlphaFraction" format="fraction"/>
+        <attr name="messageListSelectedBackgroundAlphaBackground" format="reference|color"/>
         <attr name="messageListRegularItemBackgroundColor" format="reference|color"/>
         <attr name="messageListReadItemBackgroundColor" format="reference|color"/>
         <attr name="messageListUnreadItemBackgroundColor" format="reference|color"/>
         <attr name="messageListThreadCountForegroundColor" format="reference|color"/>
         <attr name="messageListThreadCountBackground" format="reference|color"/>
         <attr name="messageListActiveItemBackgroundColor" format="reference|color"/>
+        <attr name="messageListActiveItemBackgroundAlphaFraction" format="fraction"/>
+        <attr name="messageListActiveItemBackgroundAlphaBackground" format="reference|color"/>
         <attr name="messageListPreviewTextColor" format="reference|color"/>
         <attr name="messageListDividerColor" format="reference|color"/>
         <attr name="messageListStateIconTint" format="reference|color"/>
diff --git a/app/ui/legacy/src/main/res/values/themes.xml b/app/ui/legacy/src/main/res/values/themes.xml
index 4cc3fd819..55c4b43a1 100644
--- a/app/ui/legacy/src/main/res/values/themes.xml
+++ b/app/ui/legacy/src/main/res/values/themes.xml
@@ -16,12 +16,14 @@
         <item name="android:statusBarColor">@color/material_gray_100</item>
         <item name="toolbarColor">@color/material_gray_100</item>
 
-        <item name="colorPrimary">@color/material_blue_600</item>
-        <item name="colorPrimaryVariant">@color/material_blue_800</item>
-        <item name="colorSecondary">@color/material_pink_400</item>
-        <item name="colorSecondaryVariant">@color/material_pink_200</item>
+        <item name="colorPrimary">@color/material_gray_800</item>
+        <item name="colorPrimaryVariant">@color/material_gray_700</item>
+        <item name="colorSecondary">@color/material_pink_500</item>
+        <item name="colorSecondaryVariant">@color/material_pink_300</item>
         <item name="colorOnSecondary">#ffffff</item>
         <item name="bottomBarBackground">@color/material_gray_50</item>
+        <item name="floatingActionButtonBackgroundColor">?attr/colorPrimary</item>
+        <item name="floatingActionButtonForegroundColor">?attr/colorOnPrimary</item>
 
         <item name="toolbarStyle">@style/Widget.K9.Toolbar</item>
         <item name="preferenceTheme">@style/PreferenceThemeOverlay</item>
@@ -87,13 +89,18 @@
         <item name="iconSettingsImportStatus">@drawable/ic_import_status</item>
         <item name="textColorPrimaryRecipientDropdown">@android:color/primary_text_light</item>
         <item name="textColorSecondaryRecipientDropdown">@android:color/secondary_text_light</item>
-        <item name="messageListSelectedBackgroundColor">#ff99d9ee</item>
+        <item name="messageListSelectedCheckMarkColor">?attr/colorSecondary</item>
+        <item name="messageListSelectedBackgroundColor">?attr/colorSecondaryVariant</item>
+        <item name="messageListSelectedBackgroundAlphaFraction">33%</item>
+        <item name="messageListSelectedBackgroundAlphaBackground">?attr/colorSurface</item>
         <item name="messageListRegularItemBackgroundColor">?android:attr/windowBackground</item>
         <item name="messageListReadItemBackgroundColor">#ffd8d8d8</item>
         <item name="messageListUnreadItemBackgroundColor">?attr/messageListRegularItemBackgroundColor</item>
         <item name="messageListThreadCountForegroundColor">?android:attr/colorBackground</item>
         <item name="messageListThreadCountBackground">@drawable/thread_count_box_light</item>
-        <item name="messageListActiveItemBackgroundColor">#ff2ea7d1</item>
+        <item name="messageListActiveItemBackgroundColor">?attr/colorSecondaryVariant</item>
+        <item name="messageListActiveItemBackgroundAlphaFraction">60%</item>
+        <item name="messageListActiveItemBackgroundAlphaBackground">?attr/colorSurface</item>
         <item name="messageListPreviewTextColor">#ff696969</item>
         <item name="messageListDividerColor">#ffcccccc</item>
         <item name="messageListStateIconTint">#bbbbbb</item>
@@ -170,11 +177,13 @@
         <item name="android:statusBarColor">@color/material_gray_900</item>
         <item name="toolbarColor">@color/material_gray_900</item>
 
-        <item name="colorPrimary">@color/material_blue_400</item>
-        <item name="colorPrimaryVariant">@color/material_blue_600</item>
+        <item name="colorPrimary">@color/material_gray_100</item>
+        <item name="colorPrimaryVariant">@color/material_gray_50</item>
         <item name="colorSecondary">@color/material_pink_300</item>
         <item name="colorSecondaryVariant">@color/material_pink_500</item>
         <item name="bottomBarBackground">@color/material_gray_900</item>
+        <item name="floatingActionButtonBackgroundColor">?attr/colorPrimary</item>
+        <item name="floatingActionButtonForegroundColor">?attr/colorOnPrimary</item>
 
         <item name="toolbarStyle">@style/Widget.K9.Toolbar</item>
         <item name="preferenceTheme">@style/PreferenceThemeOverlay</item>
@@ -240,13 +249,18 @@
         <item name="iconSettingsImportStatus">@drawable/ic_import_status</item>
         <item name="textColorPrimaryRecipientDropdown">@android:color/primary_text_dark</item>
         <item name="textColorSecondaryRecipientDropdown">@android:color/secondary_text_dark</item>
-        <item name="messageListSelectedBackgroundColor">#ff347489</item>
+        <item name="messageListSelectedCheckMarkColor">?attr/colorSecondary</item>
+        <item name="messageListSelectedBackgroundColor">?attr/colorSecondaryVariant</item>
+        <item name="messageListSelectedBackgroundAlphaFraction">25%</item>
+        <item name="messageListSelectedBackgroundAlphaBackground">?attr/colorSurface</item>
         <item name="messageListRegularItemBackgroundColor">?android:attr/windowBackground</item>
         <item name="messageListReadItemBackgroundColor">?attr/messageListRegularItemBackgroundColor</item>
         <item name="messageListUnreadItemBackgroundColor">#ff505050</item>
         <item name="messageListThreadCountForegroundColor">?android:attr/colorBackground</item>
         <item name="messageListThreadCountBackground">@drawable/thread_count_box_dark</item>
-        <item name="messageListActiveItemBackgroundColor">#ff33b5e5</item>
+        <item name="messageListActiveItemBackgroundColor">?attr/colorSecondaryVariant</item>
+        <item name="messageListActiveItemBackgroundAlphaFraction">50%</item>
+        <item name="messageListActiveItemBackgroundAlphaBackground">?attr/colorSurface</item>
         <item name="messageListPreviewTextColor">#ffa0a0a0</item>
         <item name="messageListDividerColor">#ff333333</item>
         <item name="messageListStateIconTint">#777777</item>