I've only ever seen transparent ones but since I don't irrigate, I don't know of the whole range that's available.
As for sitting on the toilet waiting for the return, I have many colostomate friends who irrigate who clip the sleeve up and go about their housework, eg washing the dishes, cleaning their teeth, etc while waiting and empty the sleeve when it gets full. There really is no need to be sitting on the loo the entire time from what I've learned.
I have had an ileostomy for 30 years now due to UC.
I'm not a complete idiot - some parts of me are missing!