Cache was yellow; do you want to "tie" the series together with similar covers? Or make them totally different as with the tree books. I kind of lean toward using similar colors and fonts to tie it all together. The words and graphic will be the difference.
The tree-book series was tied together with similar cover elements: victims' legs sticking out of a tent, out of a mine cart, out of under a geocache, all with a bucolic forest background.I never really liked those covers. They smacked of juvenile-fiction pseudo-reality, as if they had been designed by urban artists with neither knowledge of nor appreciation for the North Woods.An early version of the tree-book cover for "A Venture into Murder" featured shapely gams sticking out of the mine cart -- wearing spike heels. Spike heels in the North Woods?The idea of similar cover colors is a good one and I may try the same yellow shade with the first in the series, "Season's Revenge," if I can figure out how to work a winter murder theme into it.I'm going to try to use a different headline font for each book in the series, but make each font as strikingly different from the others as possible.
Hmmm, maybe green would be good for the cover.