Traffic signs are on upright poles or lampposts, so are usually visible from some distance. You'll spot them before markings. They're often the first way you'll know there's a static hazard ahead. Shapes and colours differ:
Circles = instructions (things to do or not do)
Triangles = warnings (of particular hazards)
Rectangles = information (for you to make a choice)
The more RED, the more severe the restriction (often about speed). BLUE signs say what you must do. BROWN inform about places of interest. GREEN lead you through primary routes. BLACK & WHITE give local directions. YELLOW show temporary changes.
"Know Your Traffic Signs" [KYTS] shows you almost all combinations.