Is there a “Supporters of the Colonial Theatre “ group or organization?

Yes

Yes there is. Its tier level. For $50 a year you can be a member. At the least, you can get advance ticket sales preference which is worth it.

You would have to contact them and find out

there is a member status at several levels. depending on the level of membership different perks are awarded vis a vis preferential ticket purchases, backstage access, etc...