Color wheel for CS4!
I must look into this!
I am seriously stoked about this. I've wanted a color wheel for Photoshop for a very long time since I gave up on Painter.
/runs off to finish the valkyrie picture with his new color wheel
Funny, I use Painter for the most part, and I wish it had the color system from Photoshop. The hue ring itself is ok, but I really, really, really hate the triangle. With the square system, you can independently control saturation and brightness, but removing a point and fitting the same info in a triangle skews the relationship in a non-scientific manner. Also changing saturation becomes harder as you move towards the top or the bottom because it gets narrower.
When working in Painter, you need to rely on your eyes to pick color, unless you use RGB sliders. The color system in Painter is based on a faulty triangle. Heck, Painter doesn't even have a parameter for Brightness, because Saturation and Value were arbitarily (and thus incorrectly) set to work with the (perfectly shaped but actually very deformed depending on hue) triangle. It is very unfortunate, because the triangle system could have been great if it had correct numbers behind it.
Maybe it will work better in Photoshop since it has a scientific system, but I would still voluntarily use the triangle only if the shape of the triangle changed for each hue to show the correct relationship between lightness and chroma. If it worked like that, I would actually prefer the traingle to the square, because it would allow you to pick colors based on saturation and brightness, and at the same time lets you see the value (L in photoshop) clearly.
http://www.huevaluechroma.com/082.php (look at the second image.)
I know I am not very articulate, but if what I am saying makes no sense at all, read through huevaluechroma.com. It revolutionized my understanding of color when I did.
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I just want to help spread the word about this great plugin for Photoshop CS4. This is not an ad, the programmer is not selling anything.

http://lenwhite.com/
It adds a painter's color wheel picker to Photoshop, just like the one in Corel Painter (which I refuse to use anymore).
This is relevent to the CoH fanart community because a color wheel picker is helpful for making great fan art
For those who have never used a color wheel picker, the advantage is that color is broken down into Hue, Value, and Saturation in a very intuitive way. This is especially helpful for quickly establishing color schemes and arrangements... complimentary, analogous, split complimentary, triadic, tetradic, etc.. You can pick a color and, at a glance, see what the exact compliment will be and so fourth. Yes you can already figure this out in the regular PS color picker, but the wheel is soooooo much easier and faster.
And I would definitely recommend that anyone who is interested in learning how to really use color, or improve their ability to use color effectively, will benefit from using a color wheel.