When an FFGL plugin uses the three new Hue, Saturation and Brightness parameters in a row (FF_TYPE_HUE, FF_TYPE_SATURATION, FF_BRIGHTNESS), the Resolume UI presents a colour picker widget (with "PICK", "HSB" and "RGB" modes, and the reassignable 9-entry colour palette).
When these parameters types are used in isolation, it is possible to set a default value for them, however, when they appear in a group, the colour picker widget ignores the default values. The default colour is HSB 0,0,0.
Just noting here a separate issue is that the colour picker widget includes an "Alpha" slider which is not accessible at the moment from within an FFGL plugin, and this issue is addressed elsewhere (see: Access alpha - Issue #18).
-spxl
FFGL and colour picker widgets (v6)
Re: FFGL and colour picker widgets (v6)
The issue for the default colour is already fixed internally, but I think the fix will only be available for 7, unfortunately.