Multiple subtitles with MKVMerge

[pandabear]

Hello, I have a Blue Ray player (philips BDP3300K/55) and I want to add two subtitles to a movie in format idx/sub (because srt doesnt support text colors). I tried this with mkvmerge:

sub1= spanish
sub2= english

I save the file with no error messages from Mkvmerge in my pc and Im going to watch the movie in the TV through DLNA. The thing is that when I make the switch of subtitles the result is:

sub1= spanish
sub2= spanish

In other words, the program only duplicates the first subtitle I have added. All the information content in this one was place in the second.

I have tried using many combinations, placing the two subtitles in a idx/sub file and doing the same separately and merging them with the video and audio files... I also felt curious about mixing some formats of subtitles like "srt" and "saa" in order to find a solution, but the result was worst because the movie suddenly stopped and I had to restart the blue ray.

Is there any way to solve this? All comments will be appreciated.
Thanks in advance.

[Baldrick]

How are you testing this? Just with the blu-ray player or software player like vlc media player?

[pandabear]

Hi Baldrick. Thanks for asking.

I'm testing it with the blue-ray player. I have no problems playing movies in pc using VLC.
I should say too that when I connect the USB with the movie and many subtitles aside, the blue-ray have no problem reading the movie and the subtitles. Like this:

up.mp4
up-es.srt
up-en.srt
up-fr.srt

This way only works using a USB but no through a DLNA connection reading the files directly from my PC. And thats exactly what I'm trying to do, but in order the subtitles can be read I need to put them inside the file. MKVMERGE do the trick, but when playing the movie the blue-ray only reads the first subtitle very well, the others appears in the list but they are only duplicates of the first one.

But in place of *.srt I want to add the idx/sub format. I decided this because the last one can support texts colors and its more friendly reading subtitles in yellow instead of white in classic movies.