Before my preferred color became red, I had a very intense yellow phase. In the first years with fisting I liked both. Especially it turned me on, standing upwards, someone kneeling in front of me, giving me a blow job, and I could relief my piss in his mouth while he fisted me - or the other way around, me fisting someone on my knees and drinking his piss. As long as I wasn't very deep and used mostly Crisco, there wasn't a big problem. But with getting deeper and using more lube, such a position can get very slippery and you need a very secure stand for fisting in such position.
For going out to fetish bars with play areas but no special fisting event taken place, I sewed into several army trousers long zippers from the front up to the waistband at the back. That is very practical if you only expect one or two short fist sessions in the evening, because with the open zipper everything is accessible and you have place for lube, gloves and poppers in the side pockets, and no problems with carrying a backpack the whole evening which could easily be stolen in a crowded bar. But such trousers could become very messy if you mix your crisco and lube with a lot of piss, which can than be very unpleasant if you want to take the train home with them. But many bars have closed now, so I rarely use this trousers now.
If you play at home you can always have a small bucket within reach if someone in the sling leaks and you're not able or willing to drink everything. You don't always have such opportunity if you play at a bigger party. So it really depends on the circumstances if pissing and fisting goes well together. For me a full bladder isn't good for relaxing, so I normally try to piss before someone wants to enter my ass.
Fetish gear and fisting goes well together, mostly on bigger parties, but it's not only leather, rubber or army, nearly everything is possible now.
When playing at home I prefer to be more or less naked. It's ok if playing in a separate play room, but I feel something overdressed playing in full gear in a normal sleeping room, and although I like my 20/30 hole rangers with their red laces, I don't like to clean up all the black spots they leave on the floor afterwards. And anyway if you have a long session most of the gear is taken off through the evening, because it becomes uncomfortable.
But I have been on a private fuck & fist party where two of the guests changed their outfits three times the night to fuck each other in a different fetish gear - I thought this was ridiculous. 🙂