Need help toon shading with color ramps

I’ve followed a tutorial which achieves exactly what I’m going for, yet their Blender seems to function differently than mine. I do everything exactly as they do in this video, yet right at the timestamp linked they show a mixing of a color map with the colorramp to define the colors separately from the ramp.

When I multiply a diffuse (converted to RGB) with the color ramp, depending on the factor, it is either the black and white colorramp values or the diffuse value, not really using the colorramp to control the diffuse as it should be.

There’s my node setup. The only workaround I can figure out is to set the colors directly in the colorramp, but then I can’t use textures created outside of the program, only flat colors. How can I fix this issue?