Right, the longest wavelength filter here is 4.4 µm [0]. In Hubble's version, the reddest filter they use is 1.6 µm on WFC3/IR [1] (which I believe is Hubble's reddest overall and limited by its optics). Four of the six filters used are outside Hubble's range.
[0] "In this case, the assigned colors are: Red: F444W Orange: F356W Green: F200W + F277W Blue: F090W + F150W"
[0] "In this case, the assigned colors are: Red: F444W Orange: F356W Green: F200W + F277W Blue: F090W + F150W"
https://webbtelescope.org/contents/media/images/2022/038/01G...
[1] https://archive.stsci.edu/prepds/relics/