RGB LED matrix board

Currently i am doing a project on LED matrix board. Right now i am using Adafruit 16x32 LED board. The codes are all working fine, but when i chained more panels, there are weird lights flickering. Is the code having problems or the connection of the chained boards the problem? Attached are my code and a picture of the lights flickering.

projectv7.ino (10 KB)

My guess is lack of power..
are you driving the leds thru the board?
I think it's only rated for 400mamps ..
leds do strange things when underpowered.