Renderers: use more reasonable default backend color

Author: ec-

code/renderer/tr_cmds.c

@@ -302,7 +302,7 @@ void RE_BeginFrame( stereoFrame_t stereoFrame ) {
 
 	backEnd.doneBloom = qfalse;
 
-	backEnd.color2D.u32 = 0;
+	backEnd.color2D.u32 = ~0U;
 
 	// check for errors
 	GL_CheckErrors();
@@ -339,7 +339,7 @@ void RE_BeginFrame( stereoFrame_t stereoFrame ) {
 					return;
 				}
 				clrcmd->colorMask = qtrue;
-#ifdef USE_FBO
+#ifdef USE_FBO
 				if ( !fboEnabled )
 #endif
 				{

code/renderervk/tr_cmds.c

@@ -305,7 +305,7 @@ void RE_BeginFrame( stereoFrame_t stereoFrame ) {
 	backEnd.doneBloom = qfalse;
 #endif
 
-	backEnd.color2D.u32 = 0;
+	backEnd.color2D.u32 = ~0U;
 
 	tr.frameCount++;
 	tr.frameSceneNum = 0;