In browser can we change colors...The 64 bit are light blue, and 32 bit are light green..

I don't think so. That seems to be the default color selection for plugins.

I think that the colour difference between the two could be better defined - they look quite similar at first glance on my system. What also needs some work IMO is the difference in text colour in the fx bin when it is bypassed or not (assuming it's still the same as X3).

X3 is not the current version and will not get any more updates. 

Ok, something for a "punch" list!
 
 

In the mean time, you might be able to use plugin manager to separate 64/32 plugins in the list to make it more obvious which are which
 
UPDATE:  With a brief bit of fiddling around, I was able to create a custom layout that is identical to the default, but has the 32 bit plugs in a separate folder.  This was done by creating a new folder in the layout, adding the 32 bit plugs to the new folder, then removing them from the VST2 folder.  Finally, I saved as a new layout.
 
A quick refresh of the browser display and joy-joy.
 
This change also persists across sessions.  I closed Sonar and restarted, chose new project and the browser is displaying the plugs in the new layout.
 
Total time:  10 minutes or so ...

Good idea...I will do the same, thanks