Adding color variation to a groom usually means bouncing between the hair and a texture editor, then hoping it reads right after export. The Paint Brush tool in Ornatrix v4.0 C4D lets you skip a lot of that by painting color and bitmap textures directly onto the strands in the viewport.
In this tutorial I walk through the full practical workflow.
Setting up the data
I start by adding Edit Guides and creating a Per Vertex RGBA channel through Strand Channels. This is the channel that actually stores the painted data on the groom itself, so everything stays editable and travels with the hair.
Painting color
With the Paint Brush selected, I paint solid colors directly onto the hair and use the Flood option to fill the whole groom fast when I need a base. From there it is about building variation by hand where it matters.
Working with bitmap textures
Next I load custom PNG maps with Browse and position them right in the viewport - moving, rotating and scaling the texture, then controlling tiling so the pattern sits the way I want across the strands.
Why it matters for the pipeline
The real value is that this bakes texture-based variation into a "groom_color" channel on the groom itself. That channel is ready for export workflows like Unreal Engine, which means fewer round trips and more predictable results before anything hits the renderer.
Watch the full tutorial and more grooming workflows on my channel: https://www.youtube.com/@charlytutors/videos