I've recently seen a few 'whites' flying over hedgerows and fields, but this is the first time I've been able to get close enough for an identification. Green-veined White tends to inhabit slightly rougher areas than the Small White on my patch, with the GVW being seen in rural hedgerows, whilst the Small White is more frequently seen in gardens. The first one I saw was a freshly-emerged female:
Then I almost immediately saw a male on a dandelion 'clock'. I suspect it had also just emerged, since the seedhead isn't a food source.
Whilst the main priority of a fresh specimen is to inflate its wings, this one was also checking out her tongue function:
Although the veins on the underside of the wings appear to be green, a close-up shows that the scales are yellow and black: