Hey dude, I guess it depends on the theme.
I use turbo and had to find my own solution, although I have slight notions of css.
We had a problem with the "background-color:" of our button. I suggest you go check that button with the chrome inspect element tool, to find the class or ID that references your button, and then go to your style.scss file, look for that class or ID, and change the "background-color:" to the same color you have on desktop.
I'm sorry I couldn't explain it better but hope that helps