Grey or yellow: what colour backing board should i use on my sign?
Generally, warning signs are mounted on a yellow backing board and regulatory signs either grey or yellow. Directional signs must be mounted on grey backing boards. Yellow reflective backing boards can be very effective in drawing attention to signs mounted in shadows, such as below overhanging trees. There are some disadvantages to using backing boards: rectangular boards deprive triangular & circular traffic signs of a primary recognition aid – their silhouettes. Yellow backing boards can be environmentally intrusive, and over-use can devalue their attention-attracting benefits. Chapter 7 regulations suggest that simply increasing the size of the sign would make the sign both more noticeable and more legible.
