.mpal palette from Musecore 3 not displaying colours in Musescore 4

Hello
I use coloured fingerings for my cello teaching and set up a custom palette in Musescore 3 (attached - contains blue, orange green and red versions of each fingering). When I load this into version 4, it doesn't display the colours in the palette view, although the colour properties are still there and when inserted into the score, they display correctly
System: M1 Mac running OSX 11.7.3