Version partly reviewed: Pro 1.0
Color Mechanic is a selective colour correction/changer plug-in for all versions of Photoshop (including LE) from 4.0 and Photoshop Elements. The web site indicates that it is not compatible with Paint Shop Pro. Color Mechanic is published by Digital Light & Color.
This package comes into two versions - Color Mechanic and Color Mechanic Pro. The difference is that the pro version supports both 8 and 16-bit RGB and CMYK, whereas the standard version only supports 8-bit RGB. The regular version costs USD29.85, Pro is $49.95. The plug-in does run on a Mac PowerPC for Photoshop 5 or Photoshop Elements.
My reaction on using this program for the first time was "oh, wow". I will write a more comprehensive review in time, so this is just a very quick first pass.
Color Mechanic is added to the Filters menu. When the filter is called, the screen display two copies of the image; under each copy there is a little colour range cube. Changes that are made are displayed in the right-hand window. To change a colour, you click on the original image in the left-hand window, the selected colour is indicated in the colour cube cubes. To make a change, all you do is click on the marker underneath the preview image and drag it to the required colour. A small arrow appears showing start and finish points. The effect appears in the preview image above. There is a slider to adjust brightness. Once you made all the changes you desire, click on OK and the changes are effected in the image.
There are, of course, more options, but, in a nutshell, that's is. Color Mechanic is really a great product. Download an evaluation version and try it for yourself.
Update 5 Aug '03: Fred Bopp - a die-hard Paint Shop Pro fan - has e-mailed me to point out that Color Mechanic is compatible with PSP.