How to get rid of materials showing in the viewport when in solid mode I modeled a mesh and gave it materials. But material colors get in the way; I'd like to go on modeling and just seeing a well-contrasted, solid-light object.



I find this setup uncomfortable and I'd like it to be just solid color, for instance:



I know this is the normal, default Blender behaviour; my question is not "Why my materials doesn't show in viewport", but:

Is there a way to get rid of materials showing in viewport when in solid mode, without removing them?

EDIT: I can use matcaps, I'm using BI. Same problem with Cycles. Apparently shading is ok. I'm trying to post the blend...

blend file

EDIT2: Cycles shows the same behavior. This has been tested with an untamed Blender 2.79a just downloaded.
I'm having a bit of difficulty recreating your problem, but it's possible you have a type of viewport shading activated. Check the menu to the right inside your viewport (press 'n' if you don't see it) and look under the 'Shading' option. It should be located just beneath 'Display'. See if you have something like 'Textured Solids' checked. If you don't, an alternate way to address this problem is to apply a matcap, which you will find in shading, as well. Simply click on the picture after you tick the matcap box, and select the material you want.