Lightroom "Develop" module renders the image and shows you the expected or actual image preview. The two modules use a different color space and the only accurate preview is within Develop module at 1:1(zoom) or greater.
My monitor is not calibrated. Is this still considered to be differences in the color spaces used by Develop vs Library?
Calibrating your monitor will definitively make difference to the way images look in both modules. Here's more details on this Why is there a Significant Color Shift between Develop and Library Modes?
Let us know the outcome.
Thank you so much for the information. I tested my monitor color profile and, indeed, that is the issue. I'll get my monitor calibrated and use the correct profile.
Is there a display calibration system you recommend? Is iDisplay Pro considered one of the top ones for photography and LR use?
Thanks for the update Robert, There are many third party calibration systems available and you can go with any one of them as per your liking. We've documented a article that might help you calibrate your monitor. See How to manage color in Lightroom Classic CC