The rescue arrow was undoubtedly introduced to guide an uninformed rescuer in opening the canopy of a crashed Navy airplane. Up until at least the mid 1950s, the instructions to do so, if present at all, were marked on the fuselage in fine print. What was worse, the canopy control might very well not be near the entry to the cockpit and jet canopies were increasing made of tougher stuff than heretofore, making breaking one for entry a difficult proposition.
The earliest prominent rescue marking I could find in a brief search (and the only one on a blue airplane) was on a F9F-8 Cougar. I don't know the date of the photo but it was possibly taken during a cruise between November 1955 and August 1956 aboard Ticonderoga.
Note that the canopy release is on the very back of the canopy, not the most obvious place to look. The arrow guides the rescuer from the canopy sill back to it. However, this appears to be a very nonstandard marking. This was the eventual marking on gray/white Cougars.
The rescue arrow clearly wasn't introduced with the change to gray/white markings. None of the Navy jets I looked at that were the first with the new color scheme had it. In a review of dated photos of various airplane types, I saw no rescue arrows in any picture taken in 1956 but usually in pictures taken in 1957. There is a possibility that Douglas led the way. This is an early A4D-1 on the initial at-sea trials.
The red(ish) circle in the lower right side of the national insignia is the location of the canopy release handle. Just to the upper right side of the circle enclosing the star is what may be a small red arrow pointing to it.
The above is a different flight-test A4D-1 with a similar marking that is clearly an arrow.
However, on initial-production A4D-1s, which were among the first Navy airplanes to be delivered in the gray/white scheme, the identification of the canopy release was considerably more subtle.
At some early point in A4D production, it was decided that a canopy-jettison capability should be added and its location made a little more obvious but not as obvious as the arrow was to become.
The standard red rescue arrow was present on this A4D-1 aboard Randolph in early 1957 to direct attention to the canopy release handle since it did not yet have the canopy jettison capability.
(The addition of canopy jettison, as opposed to release, is why there are occasionally two rescue arrows on the left side of an A4D.)
The F4D followed the same evolution. No rescue marking on the early production airplanes, a small red arrow as shown here on a very early deployed Skyray, and then the standard large one.
The F4H-1 Phantoms, however, had yellow rescue arrows from its first flight in May 1958.
(The F8U-3, which flew a week or so later in early June, had a red rescue arrow.)
My guess is that the rescue arrow was changed red to yellow to avoid the connotation of danger, which would be off putting to the nonprofessional rescuer, while still attracting attention.
Rick Morgan noted: The yellow/black canopy jettison markings seem to align with use of the colors for all controls that make things leave the aircraft. EA-6s (and others I suspect) actually de-activated those handles in the about 1990 because while they’d never been used for a real emergency we had several cases where untrained ground crew pulled the handles thinking that was the way to open the canopy on deck.
More background and non-standard examples would be very welcome...