Tanya isn't wrong when she says materials don't get so much more saturated and hue-changed with higher saturation, it's been discussed that the Reinhard tonemapping (Highlight compression) that Corona uses doesn't resemble how cameras capture reality.
Not sure why Rayswitch in GI was suggested...the issue is how the material looks, not what light it casts. Best trick for consistent colors would be if Corona's 'CoronaMix' node featured "Color" mode from Photoshop, that was nested inside 'Tonemap control' so that HSL never changes and that color was on top of greyscale (or highpassed) albedo.
I am writing this complicated nonsense here just in case someone wants to lobby in Request thread to include more modes into CoronaMix ;- ). It's still lacking at least 4-6 from Photoshop.
Simple solution for now:
- Make the Diffuse color actually darker than you think it is. The true physical color of something before lights and reflection adds up is often quite different.
- Have good bump map and use correct reflection (Full white color 255/255/255 and IOR 1.52). Then adjust roughness until it looks like in reality. The reflection will desaturate your material as you will increase exposure. So it will never become so toxic.
- Last step, as I said in first sentence, Corona "renders" colors wrong when they near highlights. In Photoshop, add new Vibrance/Saturation layer with empty mask. Click on the mask, Click on 'Select'/'Color Range' from top menu, then select 'Highlights mode', set the 'Range' value somewhere between 220-255 and 'Fuzziness' until you get nice gradient that covers highlights of your image. Then use negative Vibrance (not saturation) until it looks better and you get rid of any toxic colors.