I think when speaking in terms of color, and judging whether a color is warm or cold, you have to take into consideration the totality of what warm/cold colors are, and that requires looking at the whole spectrum.
If you are judging two yellows and saying one is cooler and the other is warmer, I think it could also be said that one is less warm and the other is more warm. What you're really determining, though, is how much light/dark there is in the color (from the perspective of light versus lack of light; space).
If you look at the dynamic of color, a warm color will have half in the lighter side and half in the darker side. The lighter half is yellow, and the darker half is red.
The same dynamic is present in the cool color; You have half in the lighter side (cyan), and half in the darker side (blue).
When dark crosses with dark, you get magenta. When light crosses with light, you get green.
So a greenish-yellow would more of a Neutral Light Color. A magenta-red would be more of a Neutral Dark Color.
A yellow-red would be a Warm Color that is between light/dark. A cyan-blue would be a Cool Color between light/dark.
Color blends are basically different percentages of the dark/light sides, or the warm/cold sides.
So there is a Light/Dark color and a Warm/Cold color. They cross with each other to produce the full spectrum. When warm crosses with cold, you get neutral light or dark colors. When you cross light or dark colors, you get neutral warm or cool colors.
That is how I consider color, and the theory I follow. I don't know if Goethe's theory classifies things in this manner, but I feel how I've defined it is the best way if you want to look at color as being warm/cold.
