I do hardwood flooring for a living. Red and white oak are the most popular and cost effective choices
If you do white, go with a natural water based UV protecting finish that won't yellow. People who stain white oak are retards. If you do red oak, stain it to your hearts content.
Lighter tones are fairly muted if you have white walls. Gray was in a few years back now it's rarely done, it's a very cold office feel. Browns are always a classy choice, gives the place warmth but also ages it.
Dark/black looks awesome, especially contrasting with white/gray walls which is what everyone is doing these days. Keep in mind that you'll see every single spec of dust ok them, and if you have a pet that sheds, avoid dark flooring like the plague.
If you're picking material, do not go below select and better grade, trust me, it's not worth the "savings". If you can swing it, go with engineered hardwood and glue it to the surface, it will last you a lifetime. 100% natural hardwood is "alive" and will always shift with the environmental factors.
As far as scratching and maintenence goes, everything gets fucked up; metal, wood, concrete. If you want maintenence free cheap shit go with a laminate. It won't show damage as easily at first but it won't last more than 10 years.
