Most of the time I'm in slacker-garb, home-made t-shirt and jeans (ok, cargo's more often than straight-up jeans, these days...mmm, pockets). If you look closely, you'll notice that all my clothes are solid colours, one or two 2-colour-stripe jobbies...definetly none of the multicoloured items I see some people wear. When I was a kid, and dressing myself, I used to try and mix colours/patterns/etc, but I just couldn't take it...the look of disgust on my mom's face, "what are you doing? that doesn't go together at all!"
No guidance, no training on colour theory, I was only 7 at the time, but that didn't matter...I was supposed to know everything, and if I didn't know it, I should be able to figure it out without interrupting my parents' oh-so-important lives.
So I gave up on colour matching, and started wearing all solids, often times a consistent color swatch from head to toe, to keep things simple. Which makes me look like all the more a dork, probably. But at least it all matches.