I'm not 100% certain on this, but I'm pretty sure that the ones with white at the top were originally red, and the red color just faded off of them.
The Cub Cadet tractors of that time (1965-1967) had the same decal, also with red on it, Cub Cadet 70 and 100.
Also, I've seen a lot of Cadets that I've restored where the colored portion of the hood decal has faded to white. In the 1970s, the 1x8/1x9 tractors had long black stripe decals with either green, red, orange, or blue stripes on them, and the orange and red were really bad about fading to white. The green and blue seemed to last longer. Not to be a pain in the arse, but just thought I would throw it out there.