Lou Feck is probably best known for his cover work on the James Blish Star Trek collections. His muted and monochromatic palettes hold images which depict a lot of space together. The result seems to be a flatter depth of field, making his spaces seem more like a montage of vignettes rather than a single scene. In particular his cover for Star Trek 6 utilizes this effect. The Enterprise is flying off into space while the crew is still on the ground. This feels more montage than detail in plot.
His strongest work appears to be the works that are keyed to greens and blues, however. In Star Trek 8 he has keyed his piece to a crimson, which creates a terrific atmosphere at the topmost parts of the cover, but as we travel down the cover to the stalagmites and the spaceman, the color feels a bit more aggressive and it is difficult to follow his contrasts. The stalagmites should be in front of the spaceman but they do not feel like it. Rather the large red piece on the frock of the explorer pops to the foreground.
In the Kull cover, we get our first taste of an image which is keyed to blues, with a near compliment of red to add a bit of flair. This works incredibly well for Feck. The angles in this piece also really help the composition. It is built on three isosceles triangles lying on their side. This really emphasizes the back and forth action of the serpent and Kull.
Similarly, the cover for ice is all kehed to a blue, green gray, with just the tiniest pop of "life" in oranges and yellows. The silhouettes of the city really seem to emphasize this contrast in colors as well. They certainly set the tone for a moodier cover.
Feck's cover for Demon Seed is perhaps my favorite of those selected. The piece is keyed to a blue green once again, with red and pink and yellow dashes for pop. The gears and machine interface are so precise yet expressive, while the woman's form is entirely expressive. The wires seem to move the eye around the image, while the blacks and dark greens at the edge really play up a macabre sort of mood.