Flushing the toilet when there's nothing in it but differently coloured water is a waste, but I understand why you have to do it in a social context. I would prefer not to needlessly strain my shitty pipes, but I prioritise other people not needing to know that I piss just like they do.
Anyways, this is a very obtuse way of asking how many times does a person have to come to your apartment before you can shamelessly not flush the toilet after (visibly) peeing?
I haven't really been able to measure any discoloration shining a light between the level with the water and everything above it. Looks like the same color hex code in a photo too. I've got a septic system and one of those low flow toilets, I flush as little as possible essentially. My piss is basically just off color water but I can piss 5 times before it's like actually yellow. With my fiance traveling atm sometimes I only need to flush once a day when I shit.