Step 1

Ok, first of make an new image, 400x75, & fill with black, reset your colors, select the gradient tool & set it to difference then set it to diamond gradient.

Go wild making small & large diamonds until you get something like this, don't worry if its not, yours should be a little different.

Step 2

Next use the Glass filter with following settings

Distortion: 5
Smoothness: 3
Texture: Frosted
Scaling: 100
Invert Box: Unchecked

Step 3

Now use the Ink Outlines filter with next settings

Stoke Length: 4
Dark Intensity: 20
Light Intensity: 10

 

 

You should have something similar to mine.

Step 4

Now bring up the Hue/Saturation Box (Colorize Box: Checked ) and set the colors you want, and remember to have the colorize box checked.

Final Product

Now you have a rust metal background! Below is the final product.