Thank you, do you mean it is darker than it should be instead of lighter? Because the top is the second lighter shade. The reason I made it darker is because the light is supposed to come from an upper angle, slightly higher than 45º from the ground, so that the right ramp facing up is the brightest, but still not getting super light from glare.
The main error seems to come from the fact that I tried to reuse colors, when it should actually be one color for each specific angle of the faces. In any case there seems to be 9 visible angles, but 9 shades of every color ramp from dark to mid tones is way over what I am comfortable to work with. Even if I connect the color ramps and reuse the last two darks it would still demand a larger palette than I would like.That is why I tried to reuse the shades on faces that wouldn't touch each other, but as you can see, that is difficult to predict, there can always be a construction that would make them touch and break the sense of volume.
For instance, I know the top right ramp on the larger "dome" should be a lot darker considering the angle of light, but whenever I painted it darker, it didn't looked like a opaque prism anymore, and was implying some sort of crystal. The makeshift lighter tone seems to be acting like a back light or difuse light somehow, and adds to the shape, but it is incorrect and wasn't intentional.
Thanks again, I think I need references to study since instinct alone isn't making it.