Link I posted:
BATTERY(+) ORANGE RADIO HARNESS
ACCESSORY(+) YELLOW RADIO HARNESS
GROUND(-) BLACK RADIO HARNESS
ILLUMINATION(+) GRAY RADIO HARNESS
DIMMER(+) BROWN RADIO HARNESS
If you hook up battery, accessory, ground and speakers, it should work. If not, I think the colors on your 'adapter harness' don't match factory colors. See crutchfield link may help.
https://www.crutchfield.com/S-wxw2fah6pV7/learn/learningcenter/car/car_stereo/installation_guide.html
Battery- power all the time. So you don;t lose settings.
Accessory- turns radio on w/key
Ground - return path to battery.
Illumination - to dim radio lights with dash.
If that doesn't do it, please post link or model of radio.