GL_EXT_sRGB
http://www.opengl.org/registry/specs/EXT/sRGB.txt
GL_EXT_sRGB

	GL_FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING_EXT 0x8210
	GL_SRGB_EXT 0x8C40
	GL_SRGB_ALPHA_EXT 0x8C42
	GL_SRGB8_ALPHA8_EXT 0x8C43