Anyone with edit access to the grid can manually assign a RAG (Red/Amber/Green) status to a grid as well as to individual stages, themes, elements and tasks within the grid.
Apply a status by clicking on one of the grey circles found in the grid, theme, stage, element or task title areas, once clicked on a dropdown will appear listing the available status options, just select the one you want.
It should be noted that this setting is a manual override and not automatically-linked to task/element schedule performance per se, the vast majority of teams need human-judgement autonomy here (reflecting the fact that a RAG status often absorbs a myriad of real-world risk/issue factors).
A grid's status is now added to the dashboard overview view as another key field on which you can sort this table view (a view that is available for export or print - say as a portfolio-level, executive summary of all your live projects).