Here's a Workbench 1.3 theme I made by adjusting the Palette Prefs, WBPattern and Pointer Prefs on my 3.1 A600 (which also has a 1.3 Kickstart on the ROM switcher). I adjusted it so that the grey is more like a blue-grey, the black and white have a blue tint to them, and the standard blue has been replaced with a dull orange colour. I didn't just go and copy the 1.3 colours exactly because a lot of the GUI stuff in KS2+ depends on the palette having the colours on different pens (white and black are reversed in 1.3 and 2+). This is using a 4-colour screenmode.
Anyway, here's what it looks like:
