[mcv]

1. White

2. Light grey

3. Some other light grey

...

235. dark grey

236. slightly bluish dark grey

237. slightly yellowish dark grey

...

[GekkePrutser]

Of course, but you could ignore all the obvious ones.

Keeping track of this would also show interesting trends over time. Do web designers favour 'hard' colours or pastels? Do they favour blue or less melatonin-generating colours. Stuff like that.