Lerp / Blend color - blue+yellow and cyan+yellow

lerpColor blue yellow.pde

import processing.serial.*;
int h=40;
Serial port;

void setup() {
  size(320, 320);
  background(0);
  port = new Serial(this, "/dev/cu.usbmodem21401", 9600);
}

void draw() {

  while (port.available() > 0) {
    int i = port.read()-'A';

    boolean r = (i&1)!=0;
    boolean g = (i&2)!=0;
    boolean b = (i&4)!=0;
    boolean y = (i&8)!=0;
    boolean k = (i&16)!=0;
    boolean w = (i&32)!=0;

    color rgb = color(r?255:0, g?255:0, b?255:0);
    color rgby = y ? b&&g&&!r ? #88ff77 : b&&!r ? #00ff00 : (r||g||b) ? lerpColor(rgb, #ffff00, .5) : #ffff00 : rgb; 
    color rgbyk = k ? lerpColor(rgby, #000000, .5) : rgby ;
    color rgbykw = w ? (r||g||b||y||k) ? lerpColor(rgbyk, #ffffff, .5) : color(255) : rgbyk ;

    background(rgbykw);
  }
}

send color from buttons.ino

const int pins[] = { 8, 9, 10, 11, 12, 13 }; //red green blue yellow black white
const int numButtons = sizeof(pins) / sizeof(pins[0]);

void setup() {
  for (int i = 0; i < numButtons; i++) {
    pinMode(pins[i], INPUT_PULLUP);
  }
  Serial.begin(9600);
}

void loop() {
  char b = 0;
  for (int i = 0; i < numButtons; i++) {
    if (!digitalRead(pins[i])) b |= (1 << i);
  }
  Serial.write(b+'A');
  delay(1);
}