Prevent Q_IsColorString from asserting on negative ascii chars

code/qcommon/q_shared.h

@@ -409,7 +409,7 @@ extern	vec4_t		colorMdGrey;
 extern	vec4_t		colorDkGrey;
 
 #define Q_COLOR_ESCAPE	'^'
-#define Q_IsColorString(p)	((p) && *(p) == Q_COLOR_ESCAPE && *((p)+1) && isalnum(*((p)+1))) // ^[0-9a-zA-Z]
+qboolean Q_IsColorString(const char *p);  // ^[0-9a-zA-Z]
 
 #define COLOR_BLACK	'0'
 #define COLOR_RED	'1'