ARGB in Adobe Illustrator

Question

I need to create some icons and my client's requirements are (A: 0, R:255, G: 255, B: 255) for the background. 

I'm working on Adobe Illustrator, how do I change the Alpha?

When the background is transparent, all the color values are 0. When the background is white, all the values are 255.

I don't know how to approach this as it's my first time creating icons. 

Answer 1

You can use the opacity setting under the appearance tab to change the Transparency.