What do the white, black and yellow fonts in the driving school stand for?

White font is the lowest speed, black font is the recommended speed, and yellow font is the highest speed.

Suggested speed refers to reminding the driver of the vehicle to drive at the suggested speed. Speed limit refers to the section from this sign to the front speed limit sign or another speed limit sign with different speed limit values. The minimum speed limit refers to the minimum speed limit of the road ahead.