diff --git a/apps/blc/README.md b/apps/blc/README.md
index a3581cdc7..3d126bcf8 100644
--- a/apps/blc/README.md
+++ b/apps/blc/README.md
@@ -9,5 +9,9 @@ From top to bottom the watch face shows four rows of leds:
 * day (yellow leds, top row)
 * month (yellow leds, bottom row)
 
-As usual, luminous leds represent a logical one, dark leds a logcal '0'.
+The colors are default colors and can be changed at the settings page, also, the outer ring can be disabled.
+
+The rightmost LED represents 1, the second 2, the third 4, the next 8 and so on, i.e. values are the powers of two.
+
+As usual, luminous leds represent a logical one, and "dark" leds a logcal '0'. Dark means the color of the background.
 Widgets aren't affected and are shown as normal.