These days it's easy to change the colors of forms and buttons, but I'd like to hear what you think of it.
Personally I don't have anything against form elements colored the same way as the rest of the site, as long as it's clear where you can type your text and what is the submit button. I like having good-looking stuff on a website. ;)
However, I guess it depends on the purpose of the site and the target audience, too. If the target audience is web-savvy, I don't see anything bad about coloring the forms differently. But if the target audience would get confused, I wouldn't change the look of the forms. If I had an ecommerce site, I'd also keep my fingers off the forms. Maybe this is just my personal taste, but somehow seeing a fancy, colored form on a "serious" ecommerce site would look unprofessional, just like a colored scrollbar. A bit like a 12-year-old showing off their site and saying, "hey look what I can do, I'm über kewl!"
It's also possible to change the color of the elements when they're hovered and/or focused. I haven't seen that too frequently, but if done with good taste, and only on sites whose target audience won't get confused, I think it could even improve usability. Just like links changing their color on hover improve usability. But, again, I wouldn't do this on an ecommerce site.
What do you think? Useless, childish and distracting, or a good thing?