Fix message header background color

        android:id="@+id/participants_container"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:background="?attr/colorPrimary"

        android:background="?attr/messageHeaderBackground"

        android:clickable="true"

        android:focusable="true"

        android:foreground="?attr/selectableItemBackground"

    <declare-styleable name="K9Styles">

        <attr name="toolbarColor" format="reference|color" />

        <attr name="messageHeaderBackground" format="reference|color" />

        <attr name="bottomBarBackground" format="reference|color" />

        <attr name="iconUnifiedInbox" format="reference" />

        <attr name="iconFolder" format="reference" />

        <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="messageHeaderBackground">@color/material_gray_100</item>

        <item name="bottomBarBackground">@color/material_gray_50</item>

        <item name="toolbarStyle">@style/Widget.K9.Toolbar</item>

        <item name="colorPrimaryVariant">@color/material_blue_600</item>

        <item name="colorSecondary">@color/material_pink_300</item>

        <item name="colorSecondaryVariant">@color/material_pink_500</item>

        <item name="messageHeaderBackground">@color/material_gray_900</item>

        <item name="bottomBarBackground">@color/material_gray_900</item>

        <item name="toolbarStyle">@style/Widget.K9.Toolbar</item>