As per the planning application, the triple glazed windows are going to be framed in a grey / blue that ties in with the current grey / blue colouring of the current (original) Silver Spray building:

The front garage and sign are a lighter blue than the blue on the building:

The surrounding houses have also gone for shades of blue:

By going to Silver Spray and comparing the colours to a RAL colour chart, the colour that seems the best match is RAL 5007.

It’s hard to show this on a screen, as different monitors and different graphics cards will show the same colour differently. But here are some attempts. The first is from a Google image search on “RAL 5007”.

Then from a window company (http://www.plastixal.pl/www/fr/425,palette_de_couleurs.html) that shows different painted frames (well the corner, so the colour impact is bigger than it’ll actually be !).