why those sololearners make a question about hex color?? not anyone can memorized those color.. so stop making it.

Answer 1

Sololearn never ask you to remember all the color colors, it only want you to understand how a color can be formed by using red, green and blue hex codes.

If you understand the color codes works, you could easily guess the color that SoloLearn askes.
For example, I could easily know the #0111f0 code is blue color, #20e120 is green color and #df1020 is red color, because I understand the color code is represented by #rrggbb 2 byte hex code of each rgb colors, which the higher hex code could dominate the color.