Taking your advice into consideration I decided to draw a few variations of swords, decided to pick around 4 shades for each material, in the case of my two different metals I managed to share a couple of colours.
I am still not entirely happy with the wooden sword but it gave me the gist of the colour of the material for the handles of other blades.
I was originally trying to create a colour palette that covered most of the colour wheel ( ie red orange yellow green blue purple and pink., and use that to pick colours from as I worked. on different pieces.
I decided to start by drawing weapons as then I can experiment and see how many different kinds and variations I can create with these limited colours
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Edit:
attempted to expand a little bit by adding a copper and brass sword using similar ish shades of oranges and yellows, and I also attempted to add a few more colours to create silver trim on another sword, not too happy with its look colour wise but after 6 different attempts to draw the sword with silver trim I am struggling.
I also refined the wooden sword and gave the iron and steel styled swords an iron guard.