Built in 1997 by members of the Mattatuck Astronomical Society (MAS), the Dorrit Hoffleit observatory at White Memorial has been a tremendous asset to the club members and the public. The observatory is currently maintained and operated by MAS and the Litchfield Hills club. Its 17.5″ telescope, an integral part of the club’s public outreach efforts, has recently (2016) been upgraded with computerized “go-to” controls, vastly improving the star party experience and supplementing our members’ own equipment. The observatory is named for E. Dorrit Hoffleit (1907-2007), an American astronomer noted for her work on variable stars and star catalogs. You can read about her life and career at Wikipedia – Dorrit Hoffleit.
Read this reference to understand the color coding. In a nutshell, if you see lots of blue blocks, especially in the cloud cover section there is a high chance it will be clear then.