Swapped blue and red write commands as they where in the wrong order.

TLC5971 breakout.jpg

TLC5971.c

void setup() {
  pinMode(2, OUTPUT); // power
  pinMode(3, OUTPUT); // SDI
  pinMode(4, OUTPUT); // SCK
}


 char r[8] = { 0xFF, 0x00, 0x00 };
 char g[8] = { 0x00, 0xff, 0x00 };
 char b[8] = { 0x00, 0x00, 0xff };
 char data[4] = { 0x94, 0x50, 0x0F, 0xFF };
 int seq = 0;

void write(byte out) {
  shiftOut(3, 4, MSBFIRST, out); 
}

void loop() {
  digitalWrite(2, HIGH);
  int i = 0;
  while (i < 8) {
     if (i > 3) {
        write(b[seq]);
        write(b[seq]);
        write(g[seq]);
        write(g[seq]);
        write(r[seq]);
        write(r[seq]);
     } else {
        write(data[i]);
     }
     i++;
  }
  
  delay(1000);
  
  seq++;
  if (seq == 3) {
     seq = 0;
  }  
}