I think for the most part its better to have a good mix of the Armour. It looks a lot better than being all one MK. Lots of artwork and things can be looked up to help you make your derision, Read Fear to tread, One of the very few Blood Angels novels in the Horus heresy series. I haven't reached that far yet im just finishing Fulgrim. But if you read Fear to tread it may mention the sort of armour that they where wearing at the time. Sanguinius Was a Very proud Primark, Very Looks orientated, not as bad as the Fulgrim and his shiny Purple Tanks. But very similar, So if you read it, you may get some inspiration for your pre heresy Blood angels. If i remember at the
HH weekender. They mentioned that White scars and Dark angels are not even listed until Book 7 of the
HH campaign. And I don't expect you will see a proper listing for Blood angels until then either.
But having said that even Art work, that is well renown gets it wrong.
For instance.
This is Talos Captain of the First Claw Night lords. Being visited by Abbadons Psk (shortly after Abbadon shoots Talos with a Storm bolter at point blank range)
This is one of the more popular art works of Talos. But fluff wise it is totally wrong. In Soul Hunter it describes Talos Armour in great Detail. The lack of skilled artificers being able to produce new Armour is slim to none, So they take what they can get. In the story's Talos is described as having one of his legs in the bright Yellow of an imperial fist, after he stole part of the leg Armour. His chest plate was taken from an Ultramarine. And I seem to remember him having a gauntlet white in color, cant remember if it was from a white scars or some kind of elite troop.