Not all 16 colours are used by any theme, so no, if you change notices to something like colour index 10 (defaults to turquoise), it will not be changed by any other colour.
Your problem here isn't with mIRC, its with your understanding of a simple concept that mIRC uses a colour *palette* which is DESIGNED to make it easy to share colours without needing to redundantly assign a colour five times over (a useful feature to just about everyone but you. I personally wouldn't want to have to click 10 events just to make every single one black when I can just make them share the same index and do this via one /color command). To give different events unique colours you need to give them unique palette indexes using this system-- you haven't successfully done this yet, apparently, or your reply would not have been "it still changes all my colours". I'm not sure how many times this can be repeated: choose a colour index/slot that is *not* in use by anything else.. I do not believe that every slot is taken. If so, humour me and switch to mIRC's default colour scheme which does not make use of all colours. You will be able to change your colours then.
I'm not being rude, I'm attempting to explain this *feature* to you but I continue repeating myself over and over because you're more focused on your own frustration with your inability to configure mIRC than with understanding how mIRC actually needs to be configured. Your request probably won't be taken seriously until you show that you understand how the feature is intended to work. Once you do, you'll see that the only real issue here is the limitation of only being able to assign 16 slots, which you still claim is not the problem.
On a sidenote, there is plenty wrong with xchat and I won't even bother getting into it. But that's why you're here telling us how you want to switch to mIRC if one feature gets "fixed" instead of happily using xchat, where you presumably say nothing is wrong, isn't it?
