| GL_EXT_blend_color | |
| http://oss.sgi.com/projects/ogl-sample/registry/EXT/blend_color.txt | |
| GL_CONSTANT_COLOR_EXT 0x8001 | |
| GL_ONE_MINUS_CONSTANT_COLOR_EXT 0x8002 | |
| GL_CONSTANT_ALPHA_EXT 0x8003 | |
| GL_ONE_MINUS_CONSTANT_ALPHA_EXT 0x8004 | |
| GL_BLEND_COLOR_EXT 0x8005 | |
| void glBlendColorEXT (GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha) |