output.{h,cpp}: remove unused enum and correct a comment

src/output.cpp

@@ -148,9 +148,7 @@ bool write_color(rgb_color_t color, bool is_fg) {
 /// Since the terminfo string this function emits can potentially cause the screen to flicker, the
 /// function takes care to write as little as possible.
 ///
-/// Possible values for color are any form the FISH_COLOR_* enum and FISH_COLOR_RESET.
-/// FISH_COLOR_RESET will perform an exit_attribute_mode, even if set_color thinks it is already in
-/// FISH_COLOR_NORMAL mode.
+/// Possible values for colors are rgb_color_t colors or special values like rgb_color_t::normal() 
 ///
 /// In order to set the color to normal, three terminfo strings may have to be written.
 ///

src/output.h

@@ -14,20 +14,6 @@
 
 class env_var_t;
 
-/// Constants for various colors as used by the set_color function.
-enum {
-    FISH_COLOR_BLACK,    // 0
-    FISH_COLOR_RED,      // 1
-    FISH_COLOR_GREEN,    // 2
-    FISH_COLOR_YELLOW,   // 3
-    FISH_COLOR_BLUE,     // 4
-    FISH_COLOR_MAGENTA,  // 5
-    FISH_COLOR_CYAN,     // 6
-    FISH_COLOR_WHITE,    // 7
-    FISH_COLOR_NORMAL,   // 8 terminal default
-    FISH_COLOR_RESET     // 9
-};
-
 void set_color(rgb_color_t c, rgb_color_t c2);
 
 void writembs_check(const char *mbs, const char *mbs_name, bool critical, const char *file, long line);