I understand your use of the lab color space for information, not necesarilly actual adjustments.
I use an Apple Mac system.
One of the more useful features is the DigitalColor Meter.
This useful program can be set to open automatically, with it you can measure L*a*b values from any program that your system can display i.e. all browsers, any imaging program, email attachments etc.etc..
I know nothing of the Windows operating system, but it should have something similar, and similarly useful.
As an aside "Raw Developer" a Mac only raw developer program can display L*a*b values and also allows you to make adjustments in L*a*b.