linphone-android/res/values/digit_style.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
	<style name="DialerDigit" parent="@android:style/TextAppearance.Medium">
		<item name="android:layout_width">60dp</item>
		<item name="android:layout_height">50dp</item>
		<item name="android:textColor">@android:color/transparent</item>
		<item name="android:textSize">20sp</item>
		<item name="android:layout_margin">25dp</item>
	</style>

	<declare-styleable name="Numpad">
		<attr name="play_dtmf">
			<enum name="dont" value="0" />
			<enum name="play" value="1" />
		</attr>
	</declare-styleable>
</resources>