I want to dye some metal, what do I use?

I'm looking to die some steel for a project I'm working on. This is just sheet metal that I want to color. I'd like a few colors (five?) to work with. I'm thinking of something like concrete dye where the color is prominent and noticeable, but still transparent. I've come across Dykem dies for machining, and that looks like what I'm after. This is yard art so it will just sit outside. I know that Dykem is supposed to be removable, but is it water soluble? I'm open to other suggestions, but so far it seems like I'm going to be spending $50-$100 just for a few small bottles of colors. Can some of you metal guys throw me some ideas you may know of?

Thanks.

Steel fx patina website is where you need to go

Thanks bub.

A patina is best as recommended..

https://www.sculpturedepot.net/clay-...tina_Solutions

Thanks, that looks like what I'm after, I think. Now it's just a matter of finding the appropriate color palate.