A light color identifying method of a signal light, comprising: collecting an image comprising the signal light through an image collecting apparatus connected to a roadside device; determining a background image according to N preceding frames of images of a current frame of image, wherein N is a positive integer greater than or equal to 1; performing foreground identification on the current frame of image according to the background image to obtain a moving foreground, wherein the moving foreground represents a change of the current frame of image relative to the background image; and determining, according to the moving foreground, a light color of a light that is turned on in the current frame of image, comprising: if the current frame of image has no moving foreground identified, determining, according to a light color of a light that was turned on in a preceding frame of image, the light color of the light that is turned on in the current frame of image; wherein information of the current frame of image comprises light holder position information; and the determining further comprises: determining, according to a light holder position corresponding to the moving foreground in the current frame of image, the light color of the light that is turned on in the current frame of image, comprising: if two moving foregrounds corresponding to different light holder positions are identified in the current frame of image, determining, according to the light color of the light that was turned on in the preceding frame of image and a preset light color switching process, the light color of the light that is turned on in the current frame of image. collecting an image comprising the signal light through an image collecting apparatus connected to a roadside device; determining a background image according to N preceding frames of images of a current frame of image, wherein N is a positive integer greater than or equal to 1; performing foreground identification on the current frame of image according to the background image to obtain a moving foreground, wherein the moving foreground represents a change of the current frame of image relative to the background image; and determining, according to the moving foreground, a light color of a light that is turned on in the current frame of image, comprising: if the current frame of image has no moving foreground identified, determining, according to a light color of a light that was turned on in a preceding frame of image, the light color of the light that is turned on in the current frame of image; wherein information of the current frame of image comprises light holder position information; and the determining further comprises: determining, according to a light holder position corresponding to the moving foreground in the current frame of image, the light color of the light that is turned on in the current frame of image, comprising: if two moving foregrounds corresponding to different light holder positions are identified in the current frame of image, determining, according to the light color of the light that was turned on in the preceding frame of image and a preset light color switching process, the light color of the light that is turned on in the current frame of image. if the current frame of image has no moving foreground identified, determining, according to a light color of a light that was turned on in a preceding frame of image, the light color of the light that is turned on in the current frame of image; wherein information of the current frame of image comprises light holder position information; and the determining further comprises: determining, according to a light holder position corresponding to the moving foreground in the current frame of image, the light color of the light that is turned on in the current frame of image, comprising: if two moving foregrounds corresponding to different light holder positions are identified in the current frame of image, determining, according to the light color of the light that was turned on in the preceding frame of image and a preset light color switching process, the light color of the light that is turned on in the current frame of image.