Firstly did you know a new update was out today? Maybe this first.
Now if you can find your keyswitches do this (thanks Kotori)
To make the red keys show up do this (same procedure as in K2.0):
Open the instrument in edit mode
Activate the 'Group Editor'
Click 'Create Empty Group' (the rightmost button in the group editor)
Make sure the button 'Edit All Groups' is not activated (when it's activated it has a red background color so make sure this is not the case)
Select the newly created Group (called 'empty group') by clicking on it (now this should be the only group having the checkbox checked).
If necessary click the 'Group Start Options' button to expand this panel.
Where it says 'always' choose 'start on key' instead. Then you see two edit boxes appear on the right. Configure these to reflect the range of your keyswitch keys (eg. C0 to G0).
Now you're done (SAVE THE FILE UNDER DIFFERENT NAME SO AS NOT TO ALTER YOUR ORIGINAL STRAD) and hopefully those keys will now appear as red.
What the above does is that it creates an empty group that's activated by any key in the range you configured. Since the group doesn't contain any zones (samples) it doesn't affect the instrument but it still tricks Kontakt into showing the red keyswitch notes on the virtual keyboard.