Click on View...then Colour and Appearance
Change the material to ptc-glass.
The default colour is black, change it to whatever colour you want.
Click on Apply...then close.
The appearance of the part will apply in the assembly model unless the appearance in the assembly has been modified, in which case that will take priority.
To change the colour in assembly, select component in the dialogue box, then select the colour you want, then apply.
Note that this will only change the appearance, not the mass properties.
