simply by default, SallyAnne, because the script does not change Dynamics as it is, so if you set dynamics to random colours, you get your stroke according to the active gradient

Do I need Ofnut's path in-betweener? I don't have that. I followed the link you put in about it samj but couldn't see where I could download it.

@Sallyanne

For random colors : Stroke the path.

- Script-Fu "Selection_Transformation_1.scm"
- Select > None
- Select Paintbrush (P) > Tools options > Select a brush > Dynamics = Random Color > Dynamics Options : Color Options , gradient = Full saturation spectrum CCW , etc.
- On the path : Stroke Path > Stroke with a paint tool > Paintbrush > Emulate brush dynamics

*****
Link plugin "path-inbetweener" by Ofnuts" :
http://sourceforge.net/projects/gimp-pa ... y/download

Save as "path-inbetweener-0.0.py" in the plug-ins directory (on Linux, make it executable).

SamJ,
you wrote a complete and detailed sequence of steps for SallyAnne, ok.
In my simpler reply to her, I tried to explain that - once she has dynamics set to random colours (for instance, I keep always active this set-up) - she get the effect by default directly by your script, just clicking on "stroke selection" parameter (maybe increasing the line thickness to see it better...).An easy way if she likes that effect...

samj thanks, I will try it out later. Will see if I can download the path-inbetweener tonight.
dinasset, I am pretty slow sometimes and don't understand what is meant by 'dynamics'.

SallyAnne
look at SamJ's post, bottom-left side of Gimp main panel:
"Dynamics" and just below "Random Color"
you can set it having the "brush" tool selected
once set, you can keep it always active

testing the script with dynamic paintbrush