Pipeline color blend state (used by [RenderingDevice]). This object is used by [RenderingDevice]. The attachments that are blended together. The constant color to blend with. See also [method RenderingDevice.draw_list_set_blend_constants]. If [code]true[/code], performs the logic operation defined in [member logic_op]. The logic operation to perform for blending. Only effective if [member enable_logic_op] is [code]true[/code].