Different color new shoots is common in JM but if you have not noticed it before maybe there is something else going on.
Summer shoots having different color is possible. Keep checking to see if the laves darken to normal.
Nutrient deficiency is another possibility.
None of the above will be retained in cuttings.
Much rarer is genetic 'sport' where a bud mutates to produce a different plant. Everything past that point is essentially a different tree with new characteristics. I doubt that's what is happening but if these shoots stay different you can probably take cuttings to keep those different characteristics.