#!/usr/bin/env python
from rgbmatrix import RGBMatrix
from random import randint
import time

rows = 16
chains = 1
parallel = 1
ledMatrix = RGBMatrix(rows, chains, parallel)
height = ledMatrix.height
width = ledMatrix.width

for x in range(width):
	for y in range(height):
		r = int(y % 8 / 7.0 * 255)
		g = int(x % 8 / 7.0 * 255)
		b = int((int(x / 8) + int(y / 8) * 4) / 7.0 * 255)
		ledMatrix.SetPixel(x, y, r, g, b)
		time.sleep(0.02)

time.sleep(5)
ledMatrix.Clear()

#!/usr/bin/env python
from rgbmatrix import RGBMatrix
from random import randint
import time

rows = 16
chains = 1
parallel = 1
ledMatrix = RGBMatrix(rows, chains, parallel)
height = ledMatrix.height
width = ledMatrix.width

for x in range(width):
	for y in range(height):
		r = int(y % 8 / 7.0 * 255)
		g = int(x % 8 / 7.0 * 255)
		b = int((int(x / 8) + int(y / 8) * 4) / 7.0 * 255)
		print r
		ledMatrix.SetPixel(x, y, r, g, b)
		time.sleep(0.05)

time.sleep(5)
ledMatrix.Clear()

--- 
+++ 
@@ -15,9 +15,8 @@
 		r = int(y % 8 / 7.0 * 255)
 		g = int(x % 8 / 7.0 * 255)
 		b = int((int(x / 8) + int(y / 8) * 4) / 7.0 * 255)
-		print r
 		ledMatrix.SetPixel(x, y, r, g, b)
-		time.sleep(0.05)
+		time.sleep(0.02)
 
 time.sleep(5)
 ledMatrix.Clear()
Remove print and increase speed
