The Spruce Carpet (Thera britannica) and the Fuscous Pine Carpet (Thera variata) are species with variable wing pattern, which usually cannot be distinguished by photos.
Being quite variable in colour, Thera brittanica/variata closely resembles some forms of the Grey Pine Carpet (Thera obeliscata).

Caught in my self made moth trap.

In my yard, Hilversum, The Netherlands, 10 September 2023