CB 2.x will receive a rewrite to userlists, but I don't know if there's any plans to provide a search module to act on those userlists. It's certainly something to consider however as many have asked for it.

Any possible release date for a CB 2.x ?

No idea, other tasks continued to pile up so it's pushed development. We've plans to begin official fully force development on CB 2.x beginning of January.

Could you please tell me if I may use select fields populated with my values ?
Like :

red
blue
yellow

Then, just declare the field into search user, and be allowed to search ?

If I understand correctly you want to supply a drop-down of values to search on say a Text field. If is the case then unfortunately no. You can however within CB > Field Management create a select drop-down of the values of your choosing. Users can then edit their profiles and select a value, which you could then add to your userlist so users could then search by that field.