The Park Royals are really too late for the Woolwiches for the most part, and while people may have Silver and Green A and C class, they're no doubt fewer in number to black n tan examples.
I bought 2 green ones, but they are a bit out of step with the rest of my dark green stock, and wouldn't be seen until steams end. (I do prefer the dark green)
They spent the vast majority of their lives in black n tan.
H vans have stuck around for a good while. Just for me personally, I bought six of the fitted vans and 3 grain vans, I plan on getting 6 regular H vans but money doesn't grow on trees! Any more is IMO money better spent on CK prints to get more variety on goods trains.
There probably is a saturation with H vans and the Palvans, but as we know stock can sit for years and then end up at ludicrous prices on ebay.