Define ColorCap instead of hardcoding 100

chat.h

@@ -34,6 +34,7 @@ enum Color {
 	White, Black, Blue, Green, Red, Brown, Magenta, Orange,
 	Yellow, LightGreen, Cyan, LightCyan, LightBlue, Pink, Gray, LightGray,
 	Default = 99,
+	ColorCap,
 };
 
 enum { None, Debug, Network, IDCap = 256 };

ui.c

@@ -314,7 +314,7 @@ struct Style {
 };
 static const struct Style Reset = { A_NORMAL, Default, Default };
 
-static const short Colors[100] = {
+static const short Colors[ColorCap] = {
 	[Default]    = -1,
 	[White]      = 8 + COLOR_WHITE,
 	[Black]      = 0 + COLOR_BLACK,