add substrata colorscheme

Color-schemes.md

@@ -1437,6 +1437,34 @@ colors:
     white:   '#c1cdc1'
 ```
 
+## [substrata](https://github.com/arzg/vim-substrata)
+
+```yaml
+# Colors (substrata)
+colors:
+ primary:
+   background: '#191c25'
+   foreground: '#b5b4c9'
+ normal:
+   black:   '#2e313d'
+   red:     '#cf8164'
+   green:   '#76a065'
+   yellow:  '#ab924c'
+   blue:    '#8296b0'
+   magenta: '#a18daf'
+   cyan:    '#659ea2'
+   white:   '#b5b4c9'
+ bright:
+   black:   '#5b5f71'
+   red:     '#fe9f7c'
+   green:   '#92c47e'
+   yellow:  '#d2b45f'
+   blue:    '#a0b9d8'
+   magenta: '#c6aed7'
+   cyan:    '#7dc2c7'
+   white:   '#f0ecfe'
+```
+
 ## [Taerminal](https://github.com/cozywigwam/iterm-taerminal)
 
 ```yaml