n/colors.md: add a couple of colours

Author: Mikaela

n/colors.md

@@ -10,9 +10,15 @@ lang: en
 # Useful color codes
 
 - `#000000` - black
-- `#ffffff` - white
+- `#FFFFFF` - white
+- `#00FF00` - green
+- `#80FF00` - chartreuse
+  - `#ADFF2F` - green-yellow, near the middle of human visible spectrum
+- `#FFFF00` - yellow
+  - `#FFB700` - amber (like on old computer screens) or _sunflower mango_ or
+    _summer yellow_ or _luminous bright orange_
 - `#970000` - red
-- `#ffb700` - amber
+  - `#E34234` - vermillion
 - `#800080` - purple
   - `#8A2BE2` - blue violet via ChatGPT via [dev](https://t.me/devs_chat/131577)
     [meme](https://t.me/devs_chat/131597)