Three Stanley (GB) models I have here, in addition to the previously mentioned white and yellow highlights also have one with black. They are: No 66 10in Mk 3 Black, 02-131 No 144 - 10 Yellow and No 73 E Mk 4 White.
When Stanley came to Australia in 1966 they brought their British rather than the American style braces, using the same model numbers as Britain with an A prefix. I haven't seen any A models with black highlights but have seen white and yellow. I have two A78 10in Mk 3 one white the other yellow so my opinion is that there is no significance on the colour used within a model range. I could stand corrected (hope to be, actually) on this though.
Stanley Aus' also brought out appropriate models in the 1970's when we went metric, removing the inch size and replacing with mm ie A78 250, 300 amd 350. All the metric ones I've seen are white highlights only.
Cheers,
Geoff.