Saturation issue between ArchiCAD 28 and ArchiCAD 18

[Benluwizzy]

In ArchiCAD 28, it seems that color saturation is low compared to that of Archi 18... 18 seams brighter...

How can I resolve this?

[Karl Ottenstein]

Well, totally different rendering engines for the 3D window in 28 vs 18 I believe so only so much that you can do.   The 18 image (as earlier versions) was way oversaturated for the given texture images and any reality, so personally I consider what you show for 28 as more correct.   I assume that you are showing clients the 3D window rather than generating renders or showing them the model in BIMx?

You could certainly edit the textures that you are concerned about in any photo editor and over-saturate them (and warm them up) there to match what you show for 18.  Changing the sun in 28 to a warmer sun won't give exactly the same result as that would make the brick and stone look more similar... but the white walls would no longer be white.

[Laszlo Nagy]

It may also be possible that the textures used in v18 vs v28 are different in terms of saturation and that causes the difference in results. 

You can try opening both textures in a photo editing app to compare them, so you can see how much of the difference comes from textures and how much comes from rendering engine.