Most of users want to build their theme on they preferred colors, so in this case you don’t need to modify each component and change for example their color or font size. We use a smarter technique for this. LESS CSS supports variables and they are life savers in this case. So all you have to do is to modify theme style parameters in these files:

assets/less/bs-less/variables.less
assets/less/xenon-less/variables.less

They contain all the needed variables to change primary, secondary and main colors.

After you change these files, you need to re-compile the Xenon style files.