Update docs for FORCE_COLOR environment variable (#315)

bokub · sindresorhus · commit af4a0782458e · 2019-07-12T14:11:25.000+07:00
diff --git a/readme.md b/readme.md
@@ -151,7 +151,7 @@ Levels are as follows:
 
 Detect whether the terminal [supports color](https://github.com/chalk/supports-color). Used internally and handled for you, but exposed for convenience.
 
-Can be overridden by the user with the flags `--color` and `--no-color`. For situations where using `--color` is not possible, add the environment variable `FORCE_COLOR=1` to forcefully enable color or `FORCE_COLOR=0` to forcefully disable. The use of `FORCE_COLOR` overrides all other color support checks.
+Can be overridden by the user with the flags `--color` and `--no-color`. For situations where using `--color` is not possible, use the environment variable `FORCE_COLOR=1` (level 1), `FORCE_COLOR=2` (level 2), or `FORCE_COLOR=3` (level 3) to forcefully enable color, or `FORCE_COLOR=0` to forcefully disable. The use of `FORCE_COLOR` overrides all other color support checks.
 
 Explicit 256/Truecolor mode can be enabled using the `--color=256` and `--color=16m` flags, respectively.
 
