Thanks, it has some rusty unfinished parts that dont convey value or depth. and for some reason mods didn't let me update with a new hand but yeah...
It's not how many colors but how you use them!
That you used just four colors in this pic strikes me as a remarkable feat. The design looks interesting and you did an excellent job on the lighting and reflection. I hope your project turns out well! 
Wow, good work!