Which pre coat for water dyes

I have used water dye ( Ubeaut Blue ) brushed onto a freshly turned, very dry jarrah platter - sanded to 400 W&D in dry mode, cleaned the surface dust with metho and then applied 2 coats of a 50/50 dye mix with a fine brush.

What is the preferred seal coat to stop the colour shift ? The hoped for vibrant blue is now a dull green after the interaction with the jarrah. The lower rim where I used the red dye is of course very nice as expected. The finish is carnauba wax applied by thin layer finger wipe on - hot enough here in Brisbane that the wax was fully liquid rather than the usual soft paste.

I have natural shellac on hand so would a weak single application followed by a light 400 grit sanding stop the colour change or what is recommended. Thanks UPO