Back in the 1990s Harlequin Miniatures produced a licensed range of 28mm metal miniatures and I bought back a few of the blisters, including the robot mummy.
The Robot Mummy in the TV series was quite an aged light brown colour, certainly not white.
After painting them I started on their bases. The Robot Mummys in the TV series were running around a Victorian Gothic mansion in 1911 rather than the surface of Mars; so I decided to give them grassy temperate bases rather than Martian sand.
Here are all four.