I recently reviewed Fustle’s Causeway GR1 gravel bike and really rated it (so much so I put my hand in my pocket and bought a frameset myself) and at that time there were only the three colours avaliable, Red, Green and Blue but Fustle have just released a limited edition Gun metal colour which perfectly compliments the colour of the GRX groupset. this bike comes with the Di2 groupset so electronic shifting too.
more details here
UK GRAVEL COLLECTIVE 