Funnily enough, it might've been in the 80's or 90's, DeWalt tried to trademark the colour yellow being used on power tools. Yellow was theirs, they claimed. The thing was, at least one other maker had started using yellow - some were branded Peugeot (don't ask) and maybe JCB was in the same time-frame? Cheaper stuff, of course, and who knows whether these 'competitors' were being opportunistic in 'borrowing' Dewalt's colour scheme to up the perceived value of their tools by association.
Anyway, DeWalt pursued the matter here in the UK in the High Court. And the judge threw it out. Quite rightly, in my view - yellow is for anyone. Ha!