Update button color

<?xml version="1.0" encoding="utf-8"?>

<com.fsck.k9.ui.messageview.MessageTopView

    xmlns:android="http://schemas.android.com/apk/res/android"

<com.fsck.k9.ui.messageview.MessageTopView xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    xmlns:custom="http://schemas.android.com/apk/res-auto"

    android:id="@+id/message_view"

            <Button

                android:id="@+id/show_pictures"

                style="?android:attr/buttonStyleSmall"

                style="@style/Widget.AppCompat.Button.Colored"

                android:layout_width="wrap_content"

                android:layout_height="wrap_content"

                android:layout_gravity="right"

    </com.fsck.k9.view.NonLockingScrollView>

    <Button android:id="@+id/download_remainder"

    <Button

        android:id="@+id/download_remainder"

        style="@style/Widget.AppCompat.Button.Colored"

        android:text="@string/message_view_download_remainder"

        android:layout_height="wrap_content"

        android:visibility="gone"

        android:layout_width="fill_parent"/>

        android:layout_width="fill_parent"

        tools:visibility="visible" />

</com.fsck.k9.ui.messageview.MessageTopView>