I had a similar question about the color gradient on the darks and lights on my ASI2600MC P25, and asked Zwo Support about this. Their answer is helpful and posted below.
"Thanks for your fit files.
We have reviewed the FITS files you shared, and this is an inherent hardware characteristic of the P25 batch caused by the CMOS AVDD power supply layout, and it will not damage your camera or affect regular low-light imaging.
This horizontal color gradient originates from the inherent power supply layout of Sony’s CMOS sensor.
The AVDD power rail delivers power from one side of the sensor to the other, which inevitably creates tiny voltage drops across the horizontal pixels. This leads to inconsistent ADC reference voltages, resulting in varying Optical Black (OB) levels across columns. The gap becomes more obvious after analog gain amplification. When white balance is applied, the right side requires higher channel compensation, creating the green-left and magenta-right tint you observed.
This characteristic will not damage your camera or degrade its regular low-light deep-sky performance.
Consumer DSLRs automatically compensate for OB offset via built-in SensorVOB calibration inside the camera. However, astro cameras output unprocessed raw FITS files to preserve genuine sensor data for astronomical processing, so no in-camera auto correction is applied.This unevenness can be fully removed through standard astro calibration workflows: bias frames, dark frames and properly captured flat fields".
