머라카노?

UIButton *btnStart;

CALayer *btnLayer           = btnStart.layer;

CAGradientLayer *gLayer     = [CAGradientLayer layer];

gLayer.cornerRadius = 5;

gLayer.frame  = btnLayer.bounds;

gLayer.colors = [NSArray arrayWithObjects:

                     (id)DEFINE_SET_RGB(93, 167, 236, 0.5f).CGColor,

                     (id)DEFINE_SET_RGB(83, 154, 224, 0.7f).CGColor,

                     (id)DEFINE_SET_RGB(65, 132, 204, 1.0f).CGColor,

                     (id)DEFINE_SET_RGB(53, 117, 190, 0.8f).CGColor,

                     nil];

[btnLayer insertSublayer:gLayer atIndex:0];