Set tick to color name green instead of color code

So the tick will not be too bright in light background color scheme such
as Solarized Light.

powerlevel9k.zsh-theme

@@ -1003,7 +1003,7 @@ prompt_status() {
       "$1_prompt_segment" "$0_ERROR" "$2" "$DEFAULT_COLOR" "red" "" 'FAIL_ICON'
     fi
   elif [[ "$POWERLEVEL9K_STATUS_VERBOSE" == true || "$POWERLEVEL9K_STATUS_OK_IN_NON_VERBOSE" == true ]]; then
-    "$1_prompt_segment" "$0_OK" "$2" "$DEFAULT_COLOR" "046" "" 'OK_ICON'
+    "$1_prompt_segment" "$0_OK" "$2" "$DEFAULT_COLOR" "green" "" 'OK_ICON'
   fi
 }