I would say there are two schools of thought here for all outdoor products.
1) Subdued colors - blend in, keep a low profile
2) Bright colors - safety, ease of finding, high-style
For tents, I don't know of any brands that offer the same tent in multiple colors.
I agree, but my school of thought is
3) personal preference.
Recently bought an Integral Designs bivy that is available in bright yellow and dark green. For practical purposes, though mostly for some unforeseen future use, the yellow is probably better. I do like the way it looks, too.
My preference is usually for dark colors or earth tones, though, and after some debate, I went with the green.
Have a Mountainsmith pack on the way to try out that is available in a fairly eyecatching "lotus blue", and a rather drab "pinon green". Having seen a review with real-life pics, I thought the blue looked really good, while that shade of green varies with ad pics, and I'm not sure what it will actually look like. Went around and around over that one, too, but again ordered the green.
My old inflatable pad leaked on me last week, and I decided to update with a much lighter foam one that folds up. ThermaRest's Z-Lite is longer and less than half the weight. It's also an almost flourescent looking yellow color called "limon green"
I may or may not have checked to make sure a black stuff sack that doesn't have a use right now was an appropriate size for the pad(and tent or bivy) before ordering...