Here are a few I have of the non green boxes. All 3/8" socket sets.

From the labels it looks like it pre-dates SK-Wayne, but they could have used blue then, also. I have several SK-Wayne, but all of them are green. I'd love to come across a blue box from the S-K Wayne period. It makes sense, S-K / Lectrolite were acquired by Symington-Wayne in 1962 (AA)
From Alloy Artifacts (AA):
"Lectrolite's association with S-K appears to have been a joint marketing arrangement rather than an actual business merger. Lectrolite filed a trademark for "S-K Lectrolite" with the first use date reported as June of 1953, and later in the 1950s the companies published joint S-K/Lectrolite catalogs. In addition, Lectrolite began marking wrenches with "S-K Lectrolite"."I think the boxes in the picture are 1950's / early 1960's vintage 1953-1962+, except the blue box with the Sherman Klove label. I think it may be from the period just before the others. The tools are similar, if I remember correctly. Also, if I remember correctly, all were bought from estates, together with their contents. One of the sets was missing its 1/4" socket, that I replaced with one of the same style as the rest in the kit. Note that the 1/4" drive handles are amber, rather thaN S-K clear green, or green w/ white paint.
I just bought a blue box to refinish from another member. It is for an early 3/8" set that included swivel sockets.
Chilly