Funny story.
When I was in photo school in the mid 80's, you spent the first half year shooting nothing but 4x5 film. You go out and shoot these insanely heavy orbital cameras. You would then go in the darkroom, set up your trays; prewash, developer, stop, fix, and permawash. Turn off the lights, develop your film, usually 6 sheets at a time.
Turn the light on, the trays would be filled with from left to right; green, red, yellow, clear, and blue. If they weren't, you done something wrong and were usually looking at 6 pieces of clear plastic.
Even those of us who have been working a long time get cornfused when we break out and try something new. I recently loaded a rb67 220 film back up with 135 film (to make 24x70 panoramic images). After shooting a dozen shots, I realized the damndable dark slide was right where I left it, still in the film back. An awful lot of 135 clear film on that one.
Most people use their combi tanks as dip and dunk. Me, I like the light and use a small Jobo tank with spiral holders for real daylight development.
Hang in there.
tim in san jose