Improve description of colored option in README.md

[sahara-ooga]

• replace a image
  • I've replaced it with an example that gives a better overall picture of the coloring
• go over sample code following the change of image

[codecov-commenter]

Codecov Report

Merging #177 (33f40b1) into main (e0485ac) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #177   +/-   ##
=======================================
  Coverage   82.57%   82.57%           
=======================================
  Files          13       13           
  Lines         528      528           
=======================================
  Hits          436      436           
  Misses         92       92           

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