Usually are yellow and diamond-shaped, with black lettering or symbols.
In the U.S. a yellow diamond shape sign with a black S shape with an arrow.
That would be a double curve, it would be a black "S" on a yellow diamond shaped sign.
A yellow diamond-shaped sign with a black number inside indicates the highest safe speed limit in that area.
A black circle/diamond/square on yellow backgrounds are all route directions
Black, yellow, and red. See attached image for a picture of the German flag.
king cobra
Diamonds can be 'colourless', or yellow, or brown, or pink, or blue, or green, or black.
There are many types of black teardrop shaped bugs. It could be a type a beetle, flea, or even a tick.
Yellow diamond with a black "S"
An iron supplement, or something else, don't take it unless you're sure
Yellow (and black letters or symbols) for "ordinary hazards"; Orange for hazards created by temporary construction; or Pink for hazards caused by emergencies in the roadway ahead. Under the U.S. Manual of Uniform Traffic Control Devices.