Photoshop to vector
How to do : Metal effects in Photoshop
by - metaharpy

So, what do we need to colour metallic things.

1. an Object.

2. Colour black 100% (opacity 23%)

3. basic colour 23% Grey(#727272).

4. first shadow (3 layers of different greys, reduce opacity for different results)

5. deep shadow (several layers of black)

6. highlights
23% opacity white painted on many times (edges) or three to four times
for the reflection in the middle.

7. the smudge tool
of course , you shouldn't forget to cut off the unnecessary edges
pressure 50%. Use the smudge tool to blur the colours and make them blend.
The bright white
highlights should curve like the object's edges do! (just look below).

8. smudge it like this.

Lights on blades

a) a random blade shape
b) basic colors
c) shadows and highlights opacity 23%, as much as you like (or until it's dark enough)
d) smudge it a little bit

PS: Tutorial written with the permission of the Author!
by - metaharpy