[split] Proposed change to sticker spec for transparent stickers

[Travis Cobbs]

I split this off of the main thread to it's own proposal thread.

Thanks, Orion. I promised to get this started on the standards board forum, but I'm no longer sure if I'm a member of the standards board. (I don't have it as one of my forum badges.) Do you know where the current standards board members are listed? Since you made me a moderator, I assume I can post to the forum, but I don't think that would be appropriate if I'm not in fact one of the standards board members.