ColorWasher only works on RGB images that were opened in a graphics application, because it doesn't handle RAW data. So you need a RAW Converter to import a RAW file into a graphics application or save it to an RGB file. Although all RAW Converters offer a color correction feature, that doesn't make ColorWasher obsolete. ColorWasher can be useful even if you work with RAW files. ColorWasher manages to color correct photos much better than some RAW Converters, it gives you more flexibility and options for fine tuning the image and can produces more consistent results across a range of images.
If you want to correct a RAW file with ColorWasher, you should do as few adjustments in the RAW conversion software as possible. For example keep the color correction setting to camera defaults and don't raise brightness and contrast. Also make sure that the image is converted to 16bit to achieve a better quality in ColorWasher. On the other hand, if a RAW Converter already does a quite good job, but needs a final touch up in ColorWasher, it is better to run ColorWasher on the image that was already adjusted in the RAW Converter.
Here are some examples that demonstrate that it makes sense to use ColorWasher in addition to your RAW conversion software:
Adobe Camera RAW (ACR)
The Adobe Camera RAW plugins is delivered with Photoshop CS and Photoshop Elements 3. Two years ago it was also available as a separate product. Although it is quite a good tool, it sometimes has problems with color corrections. It can fail in some cases or produce color results that don't look that natural.
Paint Shop Pro 9 - Camera RAW Data
The RAW import feature of Paint Shop Pro 9 is limited in two ways. First of all, it can't produce 16bit images, because Paint Shop Pro doesn't support them. Secondly, it only has very few features and a very limited color correction feature.
DCRAW is a command line tool that is used by several freeware RAW Converters. It offers only a few adjustment options. In this case we used RAWDrop to convert the RAW files.
Silverfast DC Pro / DC VLT
Silverfast DC is a plugin for converting RAW files among other things. The VLT version misses some useful correction features of the Pro version, but the Pro version on the other hand is very expensive.
Bibble Pro is a applications as well as plugin for RAW conversion. It offers a lot of features and is intuitive to use.
Capture One, Breeze Browser and SharpRAW
These three tools have color correction features that are relatively good, so you probably won't need ColorWasher very often with them. Nevertheless, if you don't want to miss ColorWasher's user-friendliness, flexibility, automatic correction and color effect features, you should stick to ColorWasher.