Just had 4 new tyres fitted to my black alloys so what could the problem possibly be? Bright silver balance weights gleaming between the spokes. Aaaaargh!

Paint them black!  'Simples'.

I know but just a pain having to go and buy paint, brush and fiddle about doing it.

First world problem, my wheels and balance weights are the exact same brake dust colour!

50 Strips of Self Adhesive 5g Weights - Black (tyrebaydirect.com)

When I got my car's alloy winter wheels recoated in a "pleasant" shade of grey/gun metal, I was quite surprised to see that they fitted dark coloured balance weights.

 

But yes, very easy to sort out as I tend to do with any silver coloured wheels when "touching them up" after removing them from the car at the end of Summer or the end of Winter - even the silver coloured ones change colour over time!