The Planning Mode is toggleable mode that makes any building placed to be initially paused. You can toggle Planning Mode on and off by clicking the Planning Mode button in the bottom left corner toolbar. Buildings with paused construction are colored <b>Gray</b> as shown below.

Turning off Planning Mode does not unpause buildings that were placed while it was on. To unpause buildings placed, use the {0} (1). You can also select a building that was placed in {1} and unpause it by clicking the pause button on the Construction Inspector window (2).

Color Statuses of Construction

Buildings colored <b>White</b> are planned for construction and are currently paused. <b>Blue</b> colored buildings are currently being constructed. <b>Red</b> colored buildings are currently being deconstructed.