Index: uspace/lib/c/include/io/pixel.h
===================================================================
--- uspace/lib/c/include/io/pixel.h	(revision 2f7d77c6250db2dbaf4fc40c073fd148af44fd39)
+++ uspace/lib/c/include/io/pixel.h	(revision 587478b2be4192b088f4a64c8fde7adeec10d4eb)
@@ -50,6 +50,6 @@
 
 #define PIXEL(a, r, g, b) \
-	((((a) & 0xff) << 24) | (((r) & 0xff) << 16) | \
-	(((g) & 0xff) << 8) | ((b) & 0xff))
+	((((unsigned)(a) & 0xff) << 24) | (((unsigned)(r) & 0xff) << 16) | \
+	(((unsigned)(g) & 0xff) << 8) | ((unsigned)(b) & 0xff))
 
 typedef uint32_t pixel_t;