You can use the texture emission.
Plug in this a generated image from a rendermap and you can animate the color.
Inside Softimage, you must then animate the color how you like. Best is to use a constant shader where you animate the color over time.
The rendermap will then render out the result and overwrite an existing image so the the imagename is for every frame the same.
The scale can´t animated because there is no conversation from a color to a float/scalar which can be used as input for the scale value.
Here is a rendermap tutorial for Octane:
http://vimeo.com/25573392face