Welcome Nigel..
Hmmm wearwolfnz..

I hate to suggest makeup for a transman.. had you worn lipstick for a while before the picture was taken?
Sometimes the pigment penetrates the tissue and leaves residuals. If that is the case, if you stop wearing the bold reds/pinks it might go away. If you have to wear something for work or such and still be fem. just use lip-gloss until the pigment fades.
If that is your natural lip color, maybe try a color like French Toast or something?
Gods, there is no way to type this without sounding like a ditz..

There, now I feel better.
Makeup is not my specialty. Perhaps others can be more helpful.
And.. welcome again..