Really happy that there is a connection to CS1.
As mentioned before, it is possible to upgrade the colour for CS2. So it is possible that the colour distribution/supply for CS2 can change.
There are two ways for upgrade:
1) you need 3 CS2 of same colour and type
2) or you use 2 CS2 (same type) and 1 CS1 as joker of same colour
Here are the functions mentioned in the contract:
1)
// Upgrade 1 CS2 stamp by "upgrading" with 2 other CS2 of same type and color.
function upgradeStamp(uint256 _upgradeTokenId, uint256 _helperTokenId1, uint256 _helperTokenId2)
2)
// Upgrade 1 CS2 stamp by "upgrading" with 1 other CS2 of same type and color and 1 CS1 of same color (as a "joker").
function upgradeStampWithJoker(uint256 _upgradeTokenId, uint256 _helperTokenId, uint256 _helperCS1TokenId)