I think it was Bergman that said to always keep a white fly, that the browns couldn't refuse it, etc.

I also think that this brings up that age-old curiosity of what the trout will see - will a white caddis be refused while a natural caddis is taken? How will the color change the trout's perspective as it drifts to the edge of "the window".

Then, I think of how the longer I angle, the less I take to the stream. So, a bag full of markers just seems counter-productive (Bass_Bug has a good point about your tag line). Maybe, it's because I've never been disappointed when I've resorted to Al Troth's classic elk-hair caddis because I couldn't "match the hatch" exactly.

W/r.