1. A remote instruction system comprising a control portion, the control portion transmitting an image captured by an image capturing portion provided for capturing the image of a subject to a remote terminal, and controlling a projection portion to simultaneously project annotation images onto the subject according to an instruction issued from the remote terminal on the basis of the image captured, the control portion measuring a reflection characteristic of a portion in the surface of the subject onto which each of the annotation images is to be projected on the basis of the image captured, segregating each of the annotation images on the subject, and converting a color of each of the annotation images to be projected onto the subject on the basis of a comparison result between the color of each of the annotation images instructed by the remote terminal and the reflection characteristic of the surface of the subject to project the annotation images onto the subject.