Velvia 100 was pretty much developed for product photography were colour accuracy was important if the light temperature isn't 5500K whatever you take will not be neutral, could be better could be worse.
I spend a lot of time at Kew on dull days they often have lighting on which isn't even faintly close to daylight even shooting digitail I find it easier to wave a colour temperature meter about to get the white balance right.
Before digitail became so prevelant most people knew they had to do some correction with filters to get things right and optinammly these days scanners should be calibrated but not set to correct some of the more sophisticated drum scanners can actually adjust the tones in shadows within pictures.
An article reviewing a few colour meters
I hae the Minolta and the Gossen mostly I prefer the minolta, new these were / are 850 -1000 seconhand they mostly go for 250-300 I got lucky and paid 100 for the Minolta and 119 for the Gossen still not cheap but if you want to seriously shoot slide film they are worth having.
Gossen Sixticolour meters go for a lot less and probably do for a lot of people.
Both of osh's shots are beautiful.
Spot on tones in all of Steve's shots and I love the sky in the first one.