Process for accurate brand colors in aces?

[seth_richardson]

Struggling at the moment to get accurate pantones using aces.

This is a new struggle due to the fact that the industry standard in that sense is all in sRGB values.

I tried using the OCIO node to create a conversion of the color but it comes up short.

The values needed 108, 172, 228 what im getting using a diffuse filter to see the color with some exposure boost is 108, 167, 205.

This is using OCIO 2.0, and ACESCG config 1.2 for reference. Also using C4D built in color management. However swapping between that and vrays doesn't seem to matter.

[seth_richardson]

Or is diffuse filter just not working correctly with aces? I get wildly different results with it selected where the displayed color picker values are very skewed, where as if I just make the material diffuse with no reflection and sample the same area the colors near match the sRGB pantone.

[deyan.hadzhiev]

Hi seth_richardson, there is one problem in your OCIO node setup, but regardless of your problem, you will not get the same value as output in the VFB, because the render space is ACEScg and the values you see in the render are the ACEScg values. If you transform them from ACEScg to sRGB you should get what you expect. For reference, you should get the values of the color shown when you switch to the "Display" tab of the color swatch.

Now on your problem with the OCIO node (because you will not get the value with the setup you have shown). When you are entering a direct value in the OCIO node for input bitmap, this value has to be the one you enter as "Raw", because in your example, your are effectively having your color transformed twice leading to completely different result. The OCIO node is mostly supposed to be used with textures and entering values there should be done as "Raw" values (or if you input the value as sRGB, you need to specify "Raw" as the input space of the color transformation). See the example below:



Please note that the values shown in my example actually match the inputs, because I'm using sRGB as display correction in my example.

Since you are not using a texture, you actually do not need the OCIO node if the rendering space is already set to ACEScg from the document. You simply have to enter the input values of the pantone color in the sRGB tab of the color swatch.

I hope this clarifies the differences you are observing and answers your question. Please don't hesitate to ask more questions if you need further help.