I tried to make a multi colored smoke effect because it looks cool. Unfortunately, this feature only seems to work with Workbench Render Engine while in wireframe view. Indeed, once I try to render with Cycles or Eevee, smoke is dark and gray. I tried to type "color" as some have recommended, but this doesn't seem to help. Here's the blend file in case you're asking: https://we.tl/t-DW0AlOQdOX
Before anything else, here is an absolutely free YouTube video course on MantaFlow, which should give you everything you could possibly need. simply click the link: ( https://www.youtube.com/playlist?list=PLgO2ChD7acqElskP1q7SQKWgOybrO54Xv )
MantaFlow is still a bit finnicky, especially since recent updates removed their baking option. As such, you have to make certain you set up a few things before you begin your MantaFlow simulation.
1: It may sound silly, but: don't forget to add a light to your scene, before beginning your simulation.
Allow me to show you something you've probably shrugged off as a bug.
This is a picture of what a MantaFlow sim startup is supposed to look like.
and this is a picture of a MantaFlow sim startup when you forget to place a light in your scene (this is all in Solid Mode).
Unfortunately, MantaFlow shaders in Solid Mode are not treated the same as Blender's built-in viewport mesh-shaders, which are automatically lit, regardless of he light from your scene. So you need to add a light source, otherwise your simulation will dark i.e. unlit.
Onto the next point, which I think will help fix your issue.
Let's take a look at Principled Volume Shaders. A Principled Volume Shader will allow you to easily color and light your volumes with a few simple clicks and swishes!
Your smoke domain comes with a Principled Volume Shader if you used Quick Effects > Smoke. You can access it from the shader tab by selecting the bounding box of your smoke domain.
Let's keep it simple, and answer the question: how can you turn it blue?
With your domain selected, you can change your volume's color using the color setting from your principled volume shader!
And we're done!
I hope that this helps! you're awesome, my friend -
And keep the smoking to Blender! <3