seahawksrule is correct that it uses the color you chose. But you bring up a good point that if someone chooses gray, the tutorial is confusing.
Maybe the "skip tutorial" button can be placed in a separate balloon? Sometimes it looks like that's the only option when there is no "next" option.
I agree it's confusing when it's the only option. In fact, there's actually extra logic in there just for that -- when it's the only option, it asks for confirmation when you click it. When it's not the only option it doesn't ask for confirmation and just assumes you meant to click it.