Do we need Signpost for Linked/Grouped Dynamics only when the user changes the default behavior of how Dorico handles Linked/Grouped Dynamics? 
for instance what If I by accident Group dynamics Vertically where as group dynamics are only supposed to be done horizontally?
Groups are horizontal. Links are vertical.
You cannot group dynamics vertically. You know if dynamics are grouped/linked if you select one and others turn blue.
I think the Issue I changed the Orange color Caret color to Blue … Since I am coming from Sibelius I cant get used to the Oragne Caret Sadly.
You’re just making it harder for yourself, trying to make things like Sibelius. When I started using Dorico I was eager for the different color scheme. The constant subtle reminders that this is not my old software are helpful.
RZDorico, Mark Johnson’s advice is pretty sound. Whichever colors you use, just make sure Groups and Links use different ones, since the two concepts function and behave differently. I also came from Sibelius (and before that, Finale, which I think also used orange a lot) and I just left all Dorico’s defaults on. It made it easy for me to just learn the new software at interface-value.