I actually prefer coding CSS from scratch. Color schemes and making things look nice IS hard, for my previous and current projects I had to get feedback from friends, family, end users, graphic designers, etc. UX is hard, it's a different field than programming, but there is a method, research, and science behind it.
Here's a good resource for UX: https://goodui.org
And here is one for color theory: https://uxplanet.org/color-theory-brief-guide-for-designers-...