I really don't like any music scripts. It gets really annoying when you're in the middle of a conversation and suddenly someone's music script thing goes off. I personally don't care what sort of music people listen to, and its rather annoying when more than one person has it going at the same time.
And colors are not necessary because you can change the color of your own mIRC. On that note, people who use color scripts screw up people who change the customized color of their mIRC. For instance, say you love blue, so you have your background a dark blue and your text a light blue. If someone with color scripts changes colors and what not to dark blue or black, then you can't read what they've written.
I don't even go into chat anymore, but these things pissed me off when I did go there regularly.