I cannot change the size or color of the ass subtiles. I use them because they have features as bold or italic. Although these features are displayed corectly with vlc, as I said, color and size cannot be changed. This happens both on Linux (Ubuntu 10.04) and Windows 7.
Edited
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Guys, I found a, at least temporal, fix for this problem. It seems that the style of the ".ass" subtitles cannot be altered through VLC, which means that it has to be done through a program for such subtitles. I did that using Aegisub, a subtitles editor. All you have to do is open the subtitles file with Aegisub, go to the option Subtitles → Styles Manager and edit the Default Style or create a new style with the attributes you like (font type, size, color, etc). Then, when you use them with VLC you will have the style you defined with the subtitle editor.
Unfortunately this does not apply to MKV container formats, extracting and re-enconding the subtitles for dozens of files would take countless hours. This feature should be available by now.
An option to force SSA/ASS subtitles to use the regular styles would be great, but an option for scaling if possible would be awesome as well. An issue is that some fonts are too big or too small, nothing else is wrong with them. Something like http://i.imgur.com/U5ckiW6.png (from MX Player on android) would be so very useful.
There is a similar feature on Media Player Classic (Windows). Set overlay to VMR 9, then restart and play a video. Haali media splitter will appear in the tray, double-click, under "Options>Output" there's a setting called "SSA fontsize scale percentage". This is probably my biggest peeve with VLC, that it doesn't have an option to scale ridiculously tiny .SSA/.ASS fonts.
This feature is present in MPC as simply as shown below. 8 years later this feature is still missing in VLC. I would pay for a Media Player Classic for Android.
Just FYI, MX player pro for Android is the only video player I found that works correctly with .ass subtitles style. It would allow you to scale the subtitles font size correctly. For IOS, I can't find any video player that will do font size scaling for .ass subtitles. On Windows/Mac, SMPlayer works correctly as well for font size scaling.
I just noticed this feature was requested 12 years ago....................