Enable FORCE_COLOR and NO_COLOR for terminal colouring

Author: hugovk

sphinx/util/console.py

@@ -57,9 +57,13 @@ def term_width_line(text: str) -> str:
 
 
 def color_terminal() -> bool:
+    if 'NO_COLOR' in os.environ:
+        return False
     if sys.platform == 'win32' and colorama is not None:
         colorama.init()
         return True
+    if 'FORCE_COLOR' in os.environ:
+        return True
     if not hasattr(sys.stdout, 'isatty'):
         return False
     if not sys.stdout.isatty():