How do you keep the background light on black on a pioneer deh p5800 mp instead of changing back and forth to blue

Keep in mind that the Pioneer DEH-3087 CD is the Indonesia's Daihatsu OEM version of Pioneer DEH-2950 MP, with screen color to match the dashboard light, no remote control, and no detachable face, and with an interface to Toyota wiring. This user guide link for Pioneer DEH-2950 MP can be used for this model: www.pioneer-latin.com/downloads/crd4138a.

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Same promlem here!

Orange-12v all the time
Red-igintion switch
Yellow- to lighting switch terminal
Black- chassic grd
Green-front L spk +
Green/black -front L spk -
Gray - F R +
Gray/black- F R -
Green/red- R L +
Black/green- R L -
Gray/red- R R +
Black/gray- R R -
Blue- Control to power amp if using.

you need to turn the radio off and press the number six or number five preset button, this turns off the display reverse.

You can follow this link for the User manual
http://www.pioneerelectronics.com/PUSA/Products/CarAudioVideo/In-Dash/CD-Players/DEH-P2900MP?tab=D

go into your tools menu by pressing the center of the multi knob.(the volume control knob) turn same knob to bring up the entertainment field, press center of knob to set then turn till you get to the prompt about alternating screen. switch to no. done.

Yellow/black
If you use a cellular telephone, connect it via the
Audio Mute lead on the cellular telephone. If not,
keep the Audio Mute lead free of any connections.

Orange/white
To lighting switch terminal.

Blue/white
To system control terminal of the power amp or
Auto-antenna relay control terminal (max. 300
mA 12 V DC).

try checking on the settings maybe you accidenally change the lighting schemes in your unit.

Has it always been like this? I know that the display inverts automatically to save the life of the OEL...otherwise the brightness of the same pixels being on all the time will cause the OEL to 'burn-in' If that isn't the problem, the OEL is going bad. They can run about $100 and usually aren't worth repairing.