I want to use vertex colors as a mix factor in my material. However when I chose Add->Input the option Vertex Colors doesn't show up. Why can I not access the vertex colors data? I want to avoid using any python scripts or any workarounds with the Attribute node if possible. Using Blender 2.8.
As it turns out, Blender version 2.81 has this exact same feature natively built in. For older versions, you can enable the Node Wrangler addon for a similar feature, or you have to use the Attribute node (which for me is not the most elegant solution but works just fine). Thank you everyone for your help!