[app][github] GitHub issue label color

[at15]

Derived from #77

TODO

• [ ] find some basic colors, at least those provided by github

Ref

• https://color.adobe.com/explore
• http://nipponcolors.com
• http://colormind.io/
• https://blog.datawrapper.de/colorguide/ Your Friendly Guide to Colors in Data Visualisation
  • https://www.youtube.com/watch?v=Qj1FK8n7WgY Understanding Color

[at15]

Default color from github, NOTE: the color of text automatically changes based on label color

first row

#b60205
#d93f0b
#fbca04
#0e8a16
#1d76db
#0052cc
#5319e7

the lighter row

#e99695
#f9d0c4
#fef2c0
#c2e0c6
#bfdadc
#c5def5
#bfd4f2
#d4c5f9