[TimoJ]

@Milhouse 
i use the latest build on a intel nuc, with Estuary Modv2.

I have a gray box around the forced subs. with the same build and the same skin on a raspi3 i have normal subs without the grey box. Is this somethin that i can configure on the nuc ? With Kodi 17 there is no grey box

It´s hardcoded subs, mediainfo says

Format                                   : VobSub
Muxing-Modus                             : zlib
Codec-ID                                 : S_VOBSUB

Can you upload a short sample video that demonstrates the problem? Most of my subtitles are SRT (muxed in a MKV) and don't show any problem on a Skylake NUC.  

I have also noticed this. I just did some tests and build #0523 is the last one that doesn't have this problem. Builds after that had limited range fixed, I guess the problem comes from those code changes.
This happens only with graphical subtitles, not with srt.

File info of the subs looks like this:
Format: PGS
Muxing mode: zlib
Codec ID: S_HDMV/PGS
Codec ID/Info: Picture based subtitle format used on BDs/HD-DVDs