Now I got it, thank you for your patience.
I removed opacity 0,6 and got right color.

I will remove opacity from all lines, because I need to see original colors and to be able to identify what to change.

Unless there are some instructions, per say "map" which lines in stylesheet_colors_split.css control what on life page, how else (without proper education) to adjust store look to reasonable format?

Like you advised that line 204 controls top page color.
How to know what does line 205?

Is everything in this single file, like size of font, size of Input boxes, distance between lines, e.t.c?

Or use trials and errors to reverse engineer programmers work is my best way?