Based on this article, what is a potential weakness of traditional military camouflage?

Multi-spectral camouflage is the use of counter-surveillance techniques to conceal objects from detection across several parts of the electromagnetic spectrum at the same time. While traditional military camouflage attempts to hide an object in the visible spectrum, multi-spectral camouflage also tries to simultaneously hide objects from detection methods such as infrared, radar, and millimetre-wave radar imaging.[1][2]

Traditional military camouflage only protects against tools which use the visual spectrum to detect objects, and so if a tool is based on infrared or radar the traditional camouflage doesn't offer any protection.