[web] Introduce ColorSelector component with basic styling
Summary:
Introduce ColorSelector component with basic layout/styling.
Note: The actual functionality will be introduced in subsequent diffs.
Depends on D3660
Test Plan:
Looks as expected:
Reviewers: palys-swm, def-au1t, benschac
Reviewed By: palys-swm
Subscribers: Adrian, karol-bisztyga, benschac, yayabosh
Differential Revision: https://phabricator.ashoat.com/D3662