Trying to get back to basics to learn more about using serial data from a computer to address WS2812B LEDs. I am not much of a programmer so I would like to generate my RGB pixel array in visual programming software (Vuo.org) and send to a Teensy that will use FastLED to send the array to the LED. Where I am stuck on is; what does the data need to look like from the computer side in order to be understood by FastLED. I understand that I will need to create R G B values separately in terms of 0-255 (so red would be 255, 0 ,0 ) but I don’t understand how to send those values into the Teensy. Is there a good demo sketch that is specifically used for streaming serial data as fast as it can be sent into the LEDs? Please be gentle in your replies, thank you! 
Note, besides data in RGB format, you could also send it as HSV if you prefer to work in a certain way. Or HEX.
Rather then one at a time, it’s been suggested to read three bytes at a time for better speed.
Serial.readBytes( (char*)(&leds[i]), 3); // read three bytes at a time
If data is sent as HSV:
//Read and convert entire HSV array to RGB before showing:
Serial.readBytes( (char*)ledsHSV, NUM_LEDS * 3); // ledsHSV is second array to receive serial data
hsv2rgb_rainbow( ledsHSV, leds, NUM_LEDS); // convert
FastLED.show(); // display data
My test of reading RGB data from Glediator:
https://github.com/marmilicious/FastLED_examples/blob/master/Glediator_test1.ino
An example I had in my notes of reading serial RGB data (can’t recall where I got it):
https://gist.github.com/marmilicious/bcd3ccf8d1f4c195c153fbe06b33828e