[julia-users] Re: Diverging Colormap (like RdBu) with opacity going from 1 to 0 in the middle and back to 1

[Steven G. Johnson]

On Friday, February 12, 2016 at 5:19:28 AM UTC-5, Andreas Lobinger wrote:
>
> In the discussions about ColorTypes it showed up, that the majority 
> prefered color independent of opacity. I'd guess you need to get the 
> colormap via Colors.jl and then add the opacity information (created by 
> linscale etc.). But i'm not sure that applying a color defined as 
> color+transparency (RGBA etc.) is clearly defined in all cases. At least in 
> plotting/rendering using RGB is prevalent.
>

Matplotlib (via PyPlot) allows you to define a colormap with an alpha 
channel.