There was some precedent in color swapping Ironhide at least.
I'm not so sure that Movie Ironhide has that much to do with G1 Ironhide though other than he's a bit of an old scrapper too [good fighter].
I'd have seen an updated Ironhide more as something like a Dodge Calibur than a giant GM pick up Truck - the Universe and Timelines version are a decent attempt - but Movie Ironhide's pick up truck mode is I suppose suggestive of G2 & RID Ironhide and in terms or colors the Diaclone original - that was black.
I'm not bothered by color if there's other aspects to draw on that suggest the character - when they reuse old names/characters.
The Trax certainly might make a pretty darn fine Brawn. even if it is red. as it's 4X4 and yet it's also tiny - which works well for the character.