My main issue with the Color 35 is that it takes more trouble to collapse the lens than with a Rollei 35, along with more potential mechanical wear doing the collapse, than with a Rollei 35. This, for a travel or pocket camera that might be collapsed frequently.
I had to take the top off of mine, to re-attach the 45 degree mirror (which has also been loose in 2 other Petri models that I have). I was surprised at the relatively light weight of the focus / lens collapse gearing, given what it's being asked to do, possibly regularly.
If anyone needs to get the top off, here's the quick rundown: Remove the rewind crank, and a collar that becomes visible on the rewind post. Remove the focus wheel. Set the shutter to 1/250, and aperture to f22, just so you'll remember, for re-assembly. Remove the screw on the right-hand side of the top cover. The cover then lifts free, with the shutter and aperture control wheels staying attached to the cover. 3 things to watch: the battery check button will probably fall away from the cover; if the camera is inverted, the shutter release post will fall out; I also had a super-thin brass bushing washer fall free, which I'm pretty sure came from the focus post, which is how I put it back together.