How would I make black water?

[A_Rhuraidhi (whatever)]

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?

[LikeWaterOk (MRSim_ms)]

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

[A_Rhuraidhi (whatever)]

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