- (UIColor *)fadeFromColor:(UIColor *)fromColor toColor:(UIColor *)toColor withPercentage:(CGFloat)percentage
{
    // get the RGBA values from the colours
    CGFloat fromRed, fromGreen, fromBlue, fromAlpha;
    [fromColor getRed:&fromRed green:&fromGreen blue:&fromBlue alpha:&fromAlpha];
    
    CGFloat toRed, toGreen, toBlue, toAlpha;
    [toColor getRed:&toRed green:&toGreen blue:&toBlue alpha:&toAlpha];
    
    //calculate the actual RGBA values of the fade colour
    CGFloat red = (toRed - fromRed) * percentage + fromRed;
    CGFloat green = (toGreen - fromGreen) * percentage + fromGreen;
    CGFloat blue = (toBlue - fromBlue) * percentage + fromBlue;
    CGFloat alpha = (toAlpha - fromAlpha) * percentage + fromAlpha;
    
    // return the fade colour
    return [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
}