Question about texture color depth

Hello to all
I got a simple question.How can i select in opengl the color depth of the textures? Is it always the same with the resolutions’s color depth? Or if i cannot change it , at least how can i know what excactly is it? Also is there a way for Opengl to return the available/max texture memmory (without using any DirectX code)???

How can i select in opengl the color depth of the textures? In OpenGL 1.2, when uploading the textures, for the internal type use GL_RGB8 for 24 bit textures, GL_RGBA8 for 32 bit, and so on, the OpenGL 1.2 reference details all the possible formats.

Is it always the same with the resolutions’s color depth? No.

Also is there a way for Opengl to return the available/max texture memmory (without using any DirectX code)? No, and there is usually little reason to even worry about that.