1. An image forming apparatus configured to form an image on a sheet, comprising: a plurality of image forming units configured to form images of different colors based on image data; an intermediate transfer member; a measurement unit configured to measure a measurement image that is transferred onto the intermediate transfer member; a selecting unit configured to control the plurality of image forming units to form first measurement images of different colors, control the measurement unit to measure the first measurement images on the intermediate transfer member, and select a color of interest based on measurement results of the first measurement images; a determination unit configured to determine measurement image data based on (i) a measurement result of a first measurement image of the color of interest selected by the selecting unit and (ii) a measurement result of a first measurement image of another color; and a controller configured to control the plurality of image forming units to form second measurement images of different colors based on the measurement image data, control the measurement unit to detect a color misregistration amount for relative positions of a second measurement image of a reference color of the second measurement images and a second measurement image of another color of the second measurement images, and correct a write timing of each of the plurality of image forming units based on the color misregistration amount.