How would I make black water?

Hello to whoever has decided to click on this post, my name is A_Rhuraidhi and I have a simple question, or well that’s what it sounds like to most people.
How do I make black water?
Let me explain, so essentially I was trying to make my own design for a Cog HQ from Toontown Online, a image of a Cog HQ provided down below

Now, I was hoping to make the water black so it would look like oil, when I went to change water color I discovered that when you set it to black using the RGB, it just goes to the normal blue color.
Hence the question on, how do I actually get black water?


You need to set the water reflectance to 0, and set rgb colour to black.
You can also mess with water transparency to make it less clear and stuff


Thank you so much, I was genuinely confused on this.