One suggestion I would like to add is to cover a substantial portion of the wall area with dark grey anechoic foam panels. A room full of computers and perripherals has many small cooling fans (mine has 19 units with fans) all of these emit a substantial ammount of high frequency white noise which over time can lead to hearing loss and in the short-term is stressful. I purchased zig-zag cut anechoic panels from an audio sound studio products catalog and covered my upper walls with 2ft x 4ft panels spaced about 6" apart. Besides substantially reducing the noise it looks way cool and high tech. And, yes, it is neutral gray ...but somewhat darker than your specification. It is a bit pricy..but all the good stuff is.

I understand the need for the correct lightin conditions coming from a background of photography, but what about my eyes? I have been using a computer for my artwork for over 2 years now and have noticed my eyesight suffer, won't these new measures (if implemented) be bad for us?