Wand: How to use operations on rgba?

[zwd]

In the Wand documentation http://docs.wand-py.org/en/0.4.3/wand/i ... E_TYPES%20 is a list of colorspace types, including rgb and transparent, but rgba is missing.
How can motion blur be used on both, the rgb and the transparent? Is there a way to combine both colorspaces?

[snibgo]

A colorspace defines the meaning of the colour channels, whether or not there is an alpha channel.

When the channels represent red, green and blue, there are two major colorspaces: RGB and sRGB. sRGB is the most common. Most images you see on the web are encoded in sRGB.

I'm not familiar with Python. If you've written code and it doesn't work, you can paste it here and someone may take a look.