As mentioned in one of the answers to Why are Vulcan lips Human-reddish instead of green?, and on the Star Trek wiki article for Vulcans, it is definitely canonical that Vulcan blood is copper-based, and hence it is possible that it has a more complicated relationship with color than human blood.
An earth-based example of a copper-based blood (also referred to in the wiki) is Hemocyanin, found in Molluscs and Arthropods.
Hemocyanin is colorless when deoxygenated and dark blue when oxygenated. The blood in the circulation of these creatures,... is grey-white to pale yellow, and it turns dark blue when exposed to the oxygen in the air, as seen when they bleed. This is due to change in color of hemocyanin when it is oxidized.
While speculative, it seems not outside likelihood that the behaviour of the Vulcans' blood color is similar to the above mechanism - being a different color when in circulation and only turning bright green when exposed to air. Green, after all, (like the blue of hemocyanin) is also a color found in oxygenated copper and copper salts.
So, it could be that the reason why Spock's ears (and skin and lips, as mentioned in the previously linked question) are red, while his split lip bleeds green, is because his blood experiences changes in color when exposed to the air.
Which would mean that the color of child!Spock's ears in the Reboot are as expected.