I’d recommend experimenting with hue shifting for the buttons, since it looks like the gradient is already going from yellow to red.
Right now there’s a 2-increment difference between the button and the shadow color, but I think it’s just a slight change from making the color darker;
If you do want to try hue shifting, you could either make the base color lighter so the shadow is the same, you should increase the brighness, lower the saturation, and move it towards yellow:
Or if you want to keep the base color the same, make the shadow darker, more saturated, and move towards red: