How to access VFX Graph attributes passed as interpolants via a ShaderGraphVfxAsset ?

*EDIT* I see, exposed inputs show up in VFX Graph. Feel free to delete this.

Let's say you've got a VFX Graph modifying color and alpha per particle, usually those are read from the attribute ByteAddressBuffer.

In the case of using a ShaderGraphVfxAsset how does a VFX Shader Graph access those attributes? The first obvious place to check was the Geometry Vertex Color node, but the interpolants are coming through as 0.