I am not at all. Well, maybe a little. It depends on the bike. My son has requested that once I'm done with my Shogun--whose paint has seen better days and several spills--that I change it from burgundy to electric green. Sure, I said, because he's going to inherit it from me in a few years. (Unless I get my hands on something he wants more, of course.) I plan on upgrading the brakes and shifters and most likely replacing the handlebars.
BUT, the Centurion is another story. The components are decent even though the frame needs to be repainted. So, we'll keep what we can, probably find anything that needs to be replaced. I will be adding another brake because I'm actually going to be riding it in triathlons and I have a tendency to bomb down hills at alarming speeds. The new brake will match the original. The handlebars will be replaced with aero bars. I've already taken it to my auto body place to get the paint colors matched for the repaint. The seat post is toast, but I'm not sure I want that to be aluminum again, with the whole riding-while-dripping-water thing I'm going to be doing.
So, I'll keep what I can and change what I can't. This doesn't mean I might not end up with a couple "donor" bikes in the garage and my husband will park his car outside because the garage is becoming a bike shop...like he has been for the past three months.