How about camel or grey? I got a good camel color skirt last year at the limited's sale for $10 and it was originally $50. Its pretty straight but not pencil and it is lined wool. I like it a lot. I'm sure something similar is in the stores now.
My office is pretty casual, but I do wear skirts almost every day. My most versatile staples for winter are:
Knee lengthy corduroy skirts in black and grey
Grey pleated skirt
Black tulip style skirt
Grayish blue A-line
A few patterned skirts to lighted things up a bit - large houndstooth can be cute as well as florals and more "scenic" patterns like what you might find at Anthro.
I don't wear brown, but I think a chocolately brown or camel skirt would be a good wardrobe addition if you wear those colors.
My new obsession is full/circle skirts - I don't like to use the word circle because it makes me think of those 50's poodle skirts and that's not what I mean. Marc Jacobs had a lot of this silhouette on the runway last spring. Just above the knee length, I think it looks so girly and faboolous.
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"Don't be cool. Cool is conservative fear dressed in black. Don't limit yourself in this way." - Bruce Mau