I'm not here to propose the default color to be changed. I'm here to propose that the user is given a choice to see what colour he likes best on his own desktop .... some of you guys, ubuntu lovers, think that the human theme as it is is fine, but I can guarantee that you are not the majority..... Many people, mostly the people that don't love ubutu yet, people that don't use this forum, find the colour scheme and the title bar really boring and ugly compared to windows, and they think, in consequence, that it's less powerfull than other operating systems. As people said earlier - the first impression counts a lot, and people DO give a lot of importance to the design.
If you want to see it as a bug, the bug would be - "Ubuntu look is a barrier to the new user"
or - "most new users aren't satisfied with Ubuntu theme"
when convincing my girlfriend, that mainly uses the computer for internet and writing papers, to use linux, the most difficult part for her was the brown title bars ...