Yes,strange color on this one.It is 12 known colors on Coupe 2.4 and this one is not one of the them.
Maybe a one off by Bertone.
The Alfa Montreal was produced in the same Bertone factory at the same time.As you can se under it was possible to get colors that was not on the color charts regarding the Montreal.
It might be the same case for Dino Coupe,but who know!
Montreal paint finish codes
AR 223 Green.
AR 224 Metallic green.
AR 328 Mid-blue.
AR 521 Red.
AR 601 Orange.
AR 602 Metallic orange.
AR 727 Metallic light grey.
AR 740 Escoli grey.
AR 741 Metallic silver.
AR 825 Metallic dark brown.
AR 826 Metallic gold.
2.447.011 Italver Black.
Although they do not appear in contemporary colour charts, some Montreals were given the mid-blue finish AR 347 and metallic light brown AR 524 as alternatives to AR 328 and AR 825 respectively.