How can I change color settings

[carliedu]

Hi Valeriy,
very nice work.
I can not find all color settings (inclusive there are a lot).
Is there a rule for color settings in css.
I tried to change a lot of #xxx and #xxxxxx colors but could not find all color settings.
For example, how can I change the defult orange hover color and dates?
There could be be methods to change color settings.
Best