Opponent should have first move

I think it may be better to let the opponent (not the game creator) go first.

This would allow him to make a move right away after accepting, rather than waiting for the creator to go first.

This would imply the inviting player yields the first move to the invited player which I didn’t think was a good balance. Even though it would be a bit more engaging to just play when you accept.

So the creator always gets blue and 1st turn is randomly selected between red & blue?

That’s correct, good observation! I will make that random before implementing Blue first move always