Where do I mention skin colour? That you link brown people and immigration exhibits a particular kind of racism. Most migrants into Scotland are from England and Wales. Or would you prefer blood and soil Scots only?
The low net immigration figures for Scotland come from the Scottish govt. Scotland simply isn’t attracting people in spite of freedom of movement within the EU and UK. That tends not to include many countries with a majority “brown” populace, but skin colour isn’t something that particularly bothers me.
Approx 1 in 10 Scottish residents are “foreign born” compared to 1 in 6 for England (the English figures have a strong bias towards the south and midlands). That probably changes the cultural impact of migration. Scotland still seems to be more popular than Wales which is around 1 in 15.