a colour ramp is a number of colours of roughly the same hue (*there's a lot to discuss on an advanced level here, about ramp tinting, colour ramp mixing etc) which you use to shade something, from very dark, near black, to very bright, near white colours. The game boy palette, for example, of 4 colours, is a colour ramp. Theoretically, pure black, and pure white, only the two of them, are a colour ramp too
In this case, the 'flesh ramp' I reffered to was the collection of colours you used to shade the face. And what I said was that there was one colour you had in the hair, that (given optimization) was useful as a buffer shade in the flesh shades too. You'll notice that I basically blended everything and created one ramp for whole of the sprite. It's a juggling act, to minimize colours used, and at the same time have an end result that doesn't look too 'muddy' or monochromatic, when you do this.
And by buffer, I mean using a shade as an intermmediate step between two others, to smooth out selectively where this is needed. If I had pure white, and pure black, and one shade of gray, I'd use the shade of gray to buffer where I needed between the two to minimize the harshness. Buffering is different from Anti-aliasing in a very interesting way. Anti-alias mainly is applied to minimize the jaggy effect of pixel-art. To take away the 'blockage', really. Buffering isn't about that at all. Buffering is there to create gradients, from small to very large from one colour to another. The 'steps' might still be jaggy after you've buffered. Usually if the art style stands for it, and you want the gradients to be smoother still, and you don't mind the texture that it adds, you then dither from one shade to another...
The wiki will be a great thing.
