I need wiring color coding 4 pioneer deh 2050mpg?

Not to question you about the red being constant power but I have a pioneer deh-1600 car stereo and red is hooked to electric terminal controlled by ignition switch (on/off) and if your unit has a yellow wire that goes to constant power. The only problem with hooking up the red wire to constant would be if you happened to accidentally leave your player on it could drain the battery. Hope this helped a little. Good luck.