Don't confuse the model with the real-life era.
In the real world, painting an 071 in silver was as stupid as painting an A Class silver. The 071's were gorgeous in that livery, albeit very impractical and very short-lived.
When it comes to the 071 models, the black and silver (was it nicknamed the Engineer's livery or something?) sold out long before the IE livery, which in turn sold out long before the ST livery.
Nothing for anybody to get butthurt over, that's fact, not opinion.
Marks Models couldn't shift the IE livery 071's, while at the same time I had to scrape the dregs to get a silver and black one from DC Kits. Sold me a dud, but at least I got one, and I'll probably rope some poor sap like murphaph into fixing it for me one day.
And, the ST livery hung around well after the IE's had gone.
So, popularity of 071 liveries...
Freight grey and NIR were half-runs, I think, so it's hard to get a fair comparison. People bought them even though they were out of era, just to have. Nearly sure that Noel, who favours the BT era, has a freight grey 071.
That aside, IR won hands down, then silver and black, then IE, with ST trailing.