This might plausibly be on-topic somewhere, as I’m using it to measure LEDs among other things, but not sure where this should go. I got the cheap “VABIRA VBR-300” Lux/CCT-meter from Amazon. Amazon.com
It needs to pair with an app on your phone. The android app is very simple and just reports the current reading, it doesn’t log any data to a file.
It produces more-or-less as expected correlated color temperatures, but I find it tells me my LED is much more blue (6000K +) than I expect when close to the source (measuring around 100k lux) but then when I back off, it comes down to 4800K or less everywhere in the beam, so at least in this case, it does not measure the center substantially different in color than the edges. Also, the reported lux value seems to saturate at 133k lux.
My guess is that either a sensor, amp or ADC in this unit is saturating on higher light levels, and this happens on the red end first, making the output appear more blue overall than it really is. Makes sense as silicon photodiodes are usually more sensitive in red than blue.
IMO any decent meter would warn you somehow when the input saturates, but $30 apparently isn’t in the “decent” class.