Does Noctua have any good fans that are not that horrbile color
Instead of noctuas you could look at noiseblocker eloops on aquatuning.
yes they offer black/brown and black/grey
Cheaper fans that are very quiet and move a considerable amount of air are Cougar. Specifically the "Vortex" series. http://pcpartpicker.com/parts/case-fan/#m=150&sort=a9.
Cougar doesn't have the reputation that Noctua has yet, but they are a relative newcomer to this space.
Well, people buy cases with windows all the time, so clearly there can be a reasonable aesthetic value to custom computers...