I want to change the sub color and possibly position. SubRip aside, I am sure changing the .idx config would be a more direct solution. I hope someone will provide some guidance on this to save endless trial and error. For instance:

# Force subtitle placement relative to (org.x, org.y)
align: OFF at LEFT TOP

# ON: displays only forced subtitles, OFF: shows everything
forced subs: OFF

# The original palette of the DVD
palette: 000000, 121212, 6d6d6d, d9d9d9, 000000, 121212, 848484, cacaca, 111111, 9a9a9a, ffffff, 828282, 828282, 828282, 828282, 828282

# Custom colors (transp idxs and the four colors)
custom colors: OFF, tridx: 0000, colors: 000000, 000000, 000000, 000000

Any help is appreciated.