--- lib/ivis_opengl/screen.c
+++ lib/ivis_opengl/screen.c
@@ -168,13 +168,26 @@
 				video_flags |= SDL_HWACCEL;
 			}
 
-			SDL_GL_SetAttribute( SDL_GL_RED_SIZE, 8 );
-			SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, 8 );
-			SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, 8 );
-			SDL_GL_SetAttribute( SDL_GL_ALPHA_SIZE, 8 );
-			SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 16 );
-			SDL_GL_SetAttribute( SDL_GL_STENCIL_SIZE, 8 );
-
+			bpp = SDL_VideoModeOK(width, height, screenDepth, video_flags);
+			if (!bpp) {
+				printf("Error: Video mode %dx%d@%dbpp is not supported!\n", width, height, screenDepth);
+				return FALSE;
+			}
+			if (bpp < screenDepth) {
+				printf("Warning: Using colour depth of %d instead of %d.\n", bpp, screenDepth);
+				SDL_GL_SetAttribute( SDL_GL_RED_SIZE, 5 );
+				SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, 6 );
+				SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, 5 );
+				SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 16 );
+				SDL_GL_SetAttribute( SDL_GL_STENCIL_SIZE, 8 );
+			} else {
+				SDL_GL_SetAttribute( SDL_GL_RED_SIZE, 8 );
+				SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, 8 );
+				SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, 8 );
+				SDL_GL_SetAttribute( SDL_GL_ALPHA_SIZE, 8 );
+				SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 16 );
+				SDL_GL_SetAttribute( SDL_GL_STENCIL_SIZE, 8 );
+			}
     			// Set the double buffer OpenGL attribute.
 			SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
 		}
@@ -186,15 +199,6 @@
 			screenMode = SCREEN_WINDOWED;
 		}
 
-		bpp = SDL_VideoModeOK(width, height, screenDepth, video_flags);
-		if (!bpp) {
-			printf("Error: Video mode %dx%d@%dbpp is not supported!\n", width, height, screenDepth);
-			return FALSE;
-		}
-		if (bpp != screenDepth) {
-			debug(LOG_3D, "Warning: Using colour depth of %d instead of %d.",
-            bpp, screenDepth);
-		}
 		screen = SDL_SetVideoMode(width, height, bpp, video_flags);
 		if (!screen) {
 			printf("Error: SDL_SetVideoMode failed (%s).\n", SDL_GetError());