Apparently, Ford had decided to fight back against the successes of rally cars in the late 60s and early 70s like the Porsche 911s and the Alpine A110 with their own small purpose-built rally car named the Ford GT70.
From OCTANE MAGAZINE:
‘The GT70’s creation had been triggered by our poor performance on the 1970 Monte Carlo Rally,’ Ford Competitions manager Stuart Turner says. ‘The Escort Twin-Cams, driven by Clark, Timo Makinen and Hannu Mikkola, at best finished fifth and seventh, and had been left behind by the winning Porsche 911S and Alpine-Renault A110.’”
Thanks to Jalopnik for turning attention this burning issue!
I believe the ‘yellow’ livery is in its current state; previously, the lone prototype was in silver finish: