I’m quite late to the party here, yet after some searching I came across a source for the Record vice & plane blue. It’s called Roundel Blue
I found it Here
The color is BS381C 110 Roundel Blue – Record Vice Blue and the color code is CMYK: 44; 35; 0; 55 or sRGB: 64; 74; 114.
I hope this helps others searching.