Brick.ie The Irish Association for Adult Fans of LEGO®

Now is another step in my MOC's creation.
I want to build cistern to my truck.
I want to use chrome bricks, this is very expensive again.
I counted it and I need more then 700 chromed bricks.
Maybe I change colour, but I dont have to buy everything now

I started to model container.
I need around 30-40 such pieces.

What do you think?
Any idea about the colour?