How to make blurred smoke enough visible with an orange background I'm trying to learn how to make the smoke in blender and I found this tutorial. I tried to apply the tecnique to my specific situation. Infact I'm creating a 2D animation with a man that brings his hand / lighter to the mouth/cigarette and he lights it up. The author of the tutorial used a black background and with it the blurred/smoke is very well visible,BUT in my scenario,I'm using an orange background and my smoke is not clear. But if I make the background invisible,I can see it. I think that I should adjust some parameter but I don't know which and where it could be. Check the attached blender file to understand. Thanks. 

In the pic below you can see where the smoke is,but with a lot of difficult :



instead,on this pic,you can see it very clear :



and here you can see the picture of the node tree...
The two things that are most likely to help are density and colour. 

In your smoke shader, run the density factor through a math node. Use either multiply or power with a value that suits your taste. 

Also, use a colour with better contrast against orange. Blue would be my choice since it's opposite to orange. 

Okay, here's the changed portion of the node tree:


Notice the frames labelled "Smoke colour" and "'Density' multiplier". It is that transparency shader which lends the contrasting colour to the smoke against the background, effectively filtering the colour.

The density multiplier allows fine control of the smoke texture's rendering. By first multiplying the value various pixels can be moved above or below a value of 1.0. Passing this through a power (read: exponential) node then amplifies the gradient.

Updated .blend