Missing colour options for Materials

I have some simple type in dimensions. I Applied a plastic material, click on the Arrow to see all the shapes that make up the type (e.g, Side, Front). Click on the 'side' and In the properties I'm expecting to see the Base Colour to change??. But Im only seeing co-ordinates? Why is this missing.

Sorry, I have tried differnent materials and the poperties stay the same.

3.4

Mac10.14.6

thanks

lister