It was a light night this week for the Westford Planning Board, both figuratively and literally.

In addition to continuing talk on changes to the Red Hat campus and a delay on action relating to storm water at Kimball Farm, the focus on Monday night at Town Hall came from a proposed modification on the Cornerstone project.

The amendment requested by Cornerstone representatives asked for several changes, most notably removing the prohibition on internally lit signs in place for the project.

Following an earlier discussion with the board on the subject several weeks ago, Cornerstone attorney Douglas Deschenes and Cornerstone developer Robert Walker provided examples of externally and internally lit signs throughout the area.

The pair also offered an amended set of rules for signage that would be given to lease holders requiring internally lit channel letter LED signs and prohibiting “box” signs, signs with blinking or moving lights, exposed tube neon signs and temporary paper signs among others.

While Deschenes and Walker attempted to echo the Board’s wishes for a single type of sign for all stores at the project, only with a change from external to internal lighting, Planning Board chairman Michael Green was disappointed that a request for a change had come this late in construction with what he believed to be inadequate attempts at working with externally lit signs.

Although it appeared at times that the discussion would also include limits on the brightness of signs at the development, that issue was held for another day, with Chairman Green limiting talk to the motion on removing the earlier prohibition on internally lit signs.

The motion, which also included wording to place several buildings on the lot at two stories following discussions at earlier meetings, was approved 5-0.

Earlier motions made during the meeting were passed with only four members, but Board member Dennis Galvin, who was not expected to attend due to a cold, arrived in time for the Cornerstone discussion.