Adult apterae of Aphis ulicis are dark blackish green, with the abdominal dorsum shiny black, but usually covered with greyish wax powdering. The legs and antennae are largely pale.  See 'Further Information' link below for more detail.

(if recorded on Gorse)

Please provide close up photographs and state whether recorded on Gorse.

Found on Gorse (monophagous)

Most likely to be encountered from late spring to autumn.

The species is usually ant attended.

Thought to be common in Britain, but possibly under recorded.

Rarely recorded in Leicestershire and Rutland.

https://influentialpoints.com/Gallery/Aphis_ulicis_Gorse_aphid.htm