diff --git a/README.md b/README.md
index 6e8169a..3993533 100644
--- a/README.md
+++ b/README.md
@@ -38,6 +38,7 @@ The command-line interface is straightforward as reflected in the output from
       -L, --list-devices          List available serial devices
       -l, --log <filename>        Log to file
       -m, --map <flags>           Map special characters
+      -c, --color <0..255>        Colorize tio text (default: 15)
       -v, --version               Display version
       -h, --help                  Display help