Open any image, then
Image>Scale image... un-chain width+height and set height=1 OK
Image>Scale image... un-chain width+height and set height=<original value> OK
This will turn your input image into vertical stripes.
Experiment until you find an image that produces good stripes
You can also flatten the stripes using Colors>Curves
When you have a good stripe pattern,
Colors>Colorize... and set the hue to the basic color you want
To create highlights:
- new layer (transparent)
- FG = white
- use blend tool with gradient=FG to transparent, shape=radial to create 3 or 4 circular areas of white fading to nothing
- layer mode = overlay
- reduce opacity to taste
eg.
