If you don't want it to affect ALL of your drafting fills, you could simply turn off the Fill Foreground Color and Fill Background color check boxes in the renovation override settings.
If you mean to have a general override setting on, but make only certain fills on the plan unaffected by the override, I don't think it's possible.
You could always just assign those fills to a renovation status that isn't being overridden, and then pin those particular fills show only in the renovation filter you're using.
Scott Graham, AIA LEED BD+C
Principal | BIM Manager
Muhlenberg Greene Architects, Ltd.
Wyomissing, PA 19610
V6.5-26.0