Hallo Christoph,
Good attempt, but still insufficient for the following reasons, I think:
a) The spot lights are not white but light blue, still to reflect shining
b) The blue of the coat and the blue you use for the metal, are the same, keeping confusion between metal and clothes, and coat of arms : shey should better be distinct (like a cobalt blue for clothes for example)
c) the large blue coat worn by the knight over the armour has borders white, therefore looking like shiny, which confuses with metal. They should better be light blue and metal shiny pure white = metal have a colour different from clothing
I tried to adjust my thoughts in a drawing (increasing file size to do, then reducing back to smaller size), only to illustrate my comments.
But is was only a suggestion, don't feel committed to go further as I would myself.
Michel