If you spend some time adjusting your settings, you can get the catfish to be mostly that red'ish color with a yellow dot showing which end of the arch is the head. Or a red'ish arch fading to yellow'ish on one end.
The skull of a catfish will have a harder reflection compared to the skin. This results in a brighter color shown on your Lowrance.
I too have caught many catfish when fishing for striped fish until I got better at recognizing catfish on my equipment