My problem is very similar to yours. I'm a redhead with invisible eyebrows. I finally discovered EI Solutions Brow Enhance (http://tinyurl.com/2gkw7g). It uses a new technology to adjust to the true shade of your brows, and the texture is such that you can use a very light hand and lots of short strokes to achieve just the look you want, and it's very natural-looking.
I've tried dyeing, but I looked like Groucho Marx for the first week, and then not much was left. However, I do recommend professional shaping, which you can then maintain with the tweezers.
I've checked into Just for Redheads and wasn't impressed with their color selections.