replace more defines with enum

src/toxic_windows.h

@@ -28,14 +28,16 @@
 #define CURS_Y_OFFSET 3    /* y-axis cursor offset for chat contexts */
 
 /* Curses foreground colours (background is black) */
-#define WHITE 0
-#define GREEN 1
-#define CYAN 2
-#define RED 3
-#define BLUE 4
-#define YELLOW 5
-#define MAGENTA 6
-#define BLACK 7
+enum {
+    WHITE,
+    GREEN,
+    CYAN,
+    RED,
+    BLUE,
+    YELLOW,
+    MAGENTA,
+    BLACK,
+};
 
 /* Fixes text color problem on some terminals. 
    Uncomment if necessary */