See http://www.ralfebert.de/snippets/ios-swift/uicolor/ for the Swift version

UIColorFromRGB.h

// For example:
// UIColorFromRGBA(0xffee00, 0.5)
// UIColorFromRGB(0xffee00)

static inline UIColor *UIColorFromRGBA(int rgb, float a) {
    return [UIColor colorWithRed:((float)((rgb & 0xFF0000) >> 16))/255.0
                           green:((float)((rgb & 0xFF00) >> 8))/255.0
                            blue:((float)(rgb & 0xFF))/255.0 alpha:a];
}

static inline UIColor *UIColorFromRGB(int rgb) {
    return UIColorFromRGBA(rgb, 1.f);
}