Please look at: http://m2port.com/mempicker_help.html

Would appreciate some feedback if it works well on your (Win or Mac) platform.

memPICKER is a pixel picker tool useful for color correction, color grading and color analysis. memPICKER is able to track screen changes with up to 50 individual points and save them into a data file. Download memPICKER as Donationware for OSX and Windows platforms.

• Press 'a' on keyboard to add new pixel location, memPICKER dialog has to be selected
• Double-Click onto displayed values to delete all pixel locations
• Click onto Graph to select pixel location and display its color values
• Click 'Append' button to add RGB values and X,Y location into Data.TXT file.
• Click 'Save' button to save Data.TXT file onto same folder where the application is located.

Below you can see just a quick demonstration about evaluation of Colorchecker Charts (24 pixel points) in Excel for different Camera types.

Source: Studio Test Scenes for different Cameras by dpreview at http://www.dpreview.com/reviews/sony-alpha-7r-ii/5