A few observations, although it is sometimes difficult to be totally objective when viewing uploaded image files on the net.
Yes indeed, the colour images are over saturated, as well as exhibiting too much contrast. One thing you might want to try. I assume you are using adjustment layers, and if so change the blend mode on the Hue/Sat layer to Luminosity. By doing that you are not adding contrast to the image, only saturation. Then you can concentrate on the contrast by itself if necessary.
The B&W image shows a lot of artifacts related to over sharpening. I'm seeing a white halo around the mountains and the sky is breaking up in some areas, as well as no detail at all in the large highlight area just above the mountain. Also, in the shadow area there's a lot of noise, which is one of the effects of over sharpening an image that was underexposed initially.
Last but definitely NOT least - make sure your display is properly calibrated and profiled. A display that it to bright can really play havoc with image files, often culminating in prints that are too dark and shadows that are missing detail, as well as exhibiting noise.
Of course all I have written is based on opinion, but also on a background of many years of shooting and printing, my own files and those of my long time and very satisfied customers.
I hope this helps in some way.
Gary