The recent Godfather UHD’s have multiple scenes with forced subtitles, and like the blu-ray versions, these subs are a yellow/gold colour when played from disc. There has been some recent discussion on the Kodi and OSMC forums noting that there appears to be a Kodi-level bug in that the subtitles are not rendered in the correct colour via direct makemkv rips. It does not appear to be a makemkv bug since a user has tested an mkv with an Oppo UHD disc player and the subs were rendered in the correct colour.
I just checked Infuse on an Apple TV, and it too is failing to render in the correct colour. The subs are white, not the actual colour they are supposed to be. Small issue, but thought I’d flag it.