Traffic sign colors serve specific purposes: red means stop or prohibition, yellow warns of hazards, green provides directional guidance, blue gives informational notices like rest areas or parking, and black-and-white signs denote regulations such as speed limits.

Because blue is associated with information rather than commands, a blue stop sign disrupts this long-established system.

This break from convention can create hesitation, as drivers momentarily process the unfamiliar signal, which in some situations could increase risk.