Add colortest script for quick color testing

colortest.py

@@ -0,0 +1,12 @@
+#!/usr/bin/python3
+
+import board
+import neopixel
+import sys
+
+length = 50
+
+pixels = neopixel.NeoPixel(board.D18, length, pixel_order=neopixel.RGB, auto_write=False)
+
+pixels.fill(tuple(int(sys.argv[x]) for x in (1, 2, 3)))
+pixels.show()