M69 Practice round - yellow?

[CPCOrd]

Picked up this odd M69. The paint appears to be a WWII yellow paint, any ideas why it may have been painted yellow instead of the normal colors?

 

[US-Subs]

BS repaint for display purposes. With a solid body or fill, none had any provisions for any energetics other than propellant. I've found one that was cut on the nose and has a small void in a lead fill, but that is the only one I've ever seen. I've seen these painted yellow, blue, orange - all typically old paint like yours. An old repaint, but still a repaint.