First of all, I want to say thanks for creating such a fascinating game. And I've been enjoying it up until now, as I reached the mining part where you have to extract color from the veins. Problem is, the glyph simply doesn't work. I've had next to no trouble with other glyphs. Initially, the extract glyph worked ok, and I eventually managed to extract color from all the veins in one mine. But I've tried like 50 times in a row now at the 2nd mine, and I only made it work ONCE. I make them smaller, bigger, faster, slower etc. NOTHING seems to work.
Is there something I'm missing here? Should I have a particular heart filled, a particular color filling a heart? Should I use a certain color to draw the glyph? Do I have to stand right in front of the vein (and at the correct height)? Is there a certain requirement in the amount of color I have to use when drawing it?

Yep, you need 12 or so drops of Color to use the glyph - there should be a sound indication, when you don't have enough Color to use it.

The expose/extract glyphs were the only ones I had trouble with - not drawing them, but positioning them.

With 'expose' - you have to make sure the bottom point of the triangle is placed on the vein.

With 'extract' - make sure the center of the glyph (the 'X') is on the exposed vein.

It really helps to draw big versions of these glyphs. And, as The LxR says, you need a decent amount of Color in them too.

Must've been my lack of color when drawing it then, thanks for the help.