Hi. I recently purchased those same models on e-bay to do the exact same thing.
However I was always sceptical about the different colours mentioned and always thought that the red knight, blue knight etc. were made up as a gimick. That is until I saw a documentary on Netflix on how to make armour and in the show it also showed how to turn the metal blue. It is a heat process and the armour was acually quite impressive. It also showed how they made the gold etching that covered the edge of the armour.
I tried to find it again so that I could post the name properly it but have not had any success. I will keep looking for you.
I also checked out Youtube which had a few shorts on how to make armour and also had some on how to turn steel blue, black (they use an oil) and of course polished steel. So check out Youtube.
The blue was quite shiny and looked very nice. The red colour is also possible but I can't rememeber how they did it. But I have confirmed to myself that these colours are possible. As to how shiny they would be, quite shiny. I now feel that the armour portrayed by Aurora would not be fighting battle armour but ones used to be shown off at tournaments and jousting matches. And of course worn by only the wealthest of nobles. So they would be highly polished, gaudily coverd in feathers etc. to show off how wealthy they actually were.
I have been looking at differnt paints in order to match what I saw and I think that the lacquers mentioned earlier will be the best for my own project. You may want to experiment with them. Again check out Youtube. They have loads of shorts on model painting.
I am now also looking to buy a few more knights so that I can build them in the most disrepair possbile, just to see how far I can go in the opposite direction.
Hope this helps.
Regards.
On the bench;
Converting a 74 gun Heller kit into HMS Sutherland; 1/200
Converting Bomb Ketch into HMS Harvey; 1/200
Cleaning up an Aifix lot of 54mm figures, for converting.