The panels absorb sound super well. In reality the panels are very faint light blue/gray -leaning more towards light blue.
They work well, but I'm going to be frank about their looks. They are rectangles on your wall that have a consistent depth. This quality makes them look flat and boring in their standard 100x100cm size.
I alleviated the boring looks by cutting a few panels into three 33x100cm pieces. Mounting them in a spiraling pattern / steps to make it look more lively on the wall.
I'm very happy with the final outcome, but note that I did have to modify the panels.
Notes:
The foam can almost be cut with a wooden butter knife. Anything will cut it -I used a long kitchen knife.
Measure TWICE, cut once. And please cut all the way through in a single cut. Don't create "guiding cuts" or anything of the sort. Otherwise you'll end with jagged edges. If you screw up, just make the jagged edges face up to the ceiling or a corner.