When you view a RAW photo in RAW Power, the initial appearance may not match the final appearance. This is because the initial image is a JPEG generated by the camera. A subsequent image is generated by decoding the RAW. Decoders do not generally attempt to match the camera JPEG in appearance, but instead strive to make the best looking image they can.
You may not see this shift in other apps because most of them use an Import procedure that replaces the camera JPEG with one created by their decoder. This avoids the shift, but takes a lot longer and uses more disk space. For example, Photos and Lightroom both do this, though you can still see the difference if you view the imported image before they have a chance to replace the camera JPEG. RAW Power does not do this, both to make viewing images faster and to decrease the disk space used by the app.