The red and white LED's now change their brightness every second. On odd seconds the red LED's are brighter than on even seconds, for the blue LED's vise versa. The change of the brightness is animated

The brightness scales linear now, because I added a lookup-table for the brightness levels. I have changed the PWM of the red LED's from 8bit to 9bit PWM, now the animations at low brightness settings should look a bit smoother.

That's the function which fades the brightness:

void animateBrightness()
{ 
  if((millis() - millis_animate) >= DELAY_BRIGHTNESS)
  {
    if(second % 2)
    {
      if(brightness_red_now < (brightness_red + (DELTA_BRIGHTNESS << 1)))
        brightness_red_now += 2;

      if(brightness_white_now > brightness_white)
        brightness_white_now--;
    }
    else
    {
      if(brightness_red_now > brightness_red)
        brightness_red_now -= 2;
      
      if(brightness_white_now < (brightness_white + DELTA_BRIGHTNESS))
        brightness_white_now++;
    }

    brightness_red_log = log_brightness_9bit[brightness_red_now];
    brightness_white_log = log_brightness[brightness_white_now];
    analogWrite(WHITE_LED, brightness_white_log);

    millis_animate = millis();
  }
}

the rest of the code is on Github