The background color of a subform in datasheet view is determined NOT by Access properties, but by your Windows display properties.
Right-click anywhere on your desktop where there is not any icon.
Click the "Appearance" tab.
You will see choices for your color scheme. Click on the Window Text area. It will be the offending color of which you spoke.
The field called "Item" will change to "Window" and the "Color" field will also turn to that color.
Click the color dropdown button and change it to white or some other desired color.
Reopen Access. Your subform's background color will be the color you desire.
Michigan Dept. of Environmental Quality, Air Quality Division