I tried this last winter at the suggestion of a Scottish friend: it was delicious. But it looked a bit different in colour:
Habe ich auf Anregung einer schottischen Freundin ausprobiert im vergangenen Winter: es war köstlich. Sah aber farblich etwas anders aus...
Lovely! Mine usually starts the colour in my post, but ends up very like yours. For me, the colour appears in the first few weeks once the sugar has dissolved.
I'll try and post recipes for some more nice Scottish treats :)