Xamarin Color Helper

ColorHelpers.cs

// If you don't want to pull the whole [Splat](https://github.com/paulcbetts/splat) library over just for colors,
// here are a couple functions to help.
// Store your color values as hex-based `long`s and just convert them to native colors when you use them.
// NOTE: iOS uses RGBA floats (0..1) and Android uses ARGB ints (0..255) when converting.

// Usage example:
SomeView.SetBackgroundColor(MyAppColors.SomeGrayHighlight.AsNative());

// Core library can hold your colors:
public static class MyAppColors {
    public const long SomeGrayHighlight = 0xffcccccc;
    // ... the rest of your favorit colors ...
}

// Android conversion extension:
public static class ColorExtensions {
    public static Color AsNative(this long hexValue) {
        return Color.Argb(
            ((int)(hexValue & 0xff000000) >> 24),
            ((int)(hexValue & 0xff0000) >> 16),
            ((int)(hexValue & 0xff00) >> 8),
            ((int)(hexValue & 0xff)));
    }
}
// iOS conversion extensions:
public static UIColor AsNative(this long hexValue) {
        return UIColor.FromRGBA(
            (((float)((hexValue & 0xff0000) >> 16)) / 255.0f),
            (((float)((hexValue & 0xff00) >> 8)) / 255.0f),
            (((float)((hexValue & 0xff))) / 255.0f),
            (((float)((hexValue & 0xff000000) >> 24)) / 255.0f));
    }
}