Add Color Information to README.md

Author: tmioton

README.md

@@ -1,8 +1,8 @@
 # UltimateFlox
 2D flocking simulation using GLFW, Glad, and GLM - your very own bird box.
 
-Use the ```1``` key to switch to filled rendering mode.<br>
-Use the ```2``` key to switch to classic rendering mode.<br>
+Use the ```1``` key to switch to filled rendering mode. Pressing again will cycle through pre-defined colors.<br>
+Use the ```2``` key to switch to classic rendering mode. Pressing again will cycle through pre-defined colors.<br>
 Use the ```b``` key to toggle display of the boids.<br>
 Use the ```v``` key to toggle display of the vision radii.<br>
 Use the ```q``` key to toggle display of the quadtree (lines).<br>