Abstract: A head-up display (HUD) system is described that makes it less possible that coloring is visually recognized on a windshield even with sunglasses worn, wherein the head-up display system includes an image projector configured to project an image; and a resin film configured such that the image from the image projector is projected on the resin film, wherein the resin film is a reflective plane, and is disposed in such a manner that the incidence plane where the maximum of the absolute value of a* and the maximum of the absolute value of b* satisfy the following formulae (1) and (2) is at 90±10° to a horizontal plane.