1. A recording medium for reproducing text subtitle streams, the recording medium comprising: a data area storing at least one text subtitle stream, each text subtitle stream including a dialog style segment defining a group of region styles and a plurality of dialog presentation segments, each dialog presentation segment containing at least one region of dialog text and each region of dialog text being linked to a selected one of the group of region styles, wherein the dialog style segment further defines palette information, and each dialog presentation segment further contains a palette update flag which indicates whether to use the palette information defined in the dialog style segment or to use new palette information when reproducing the each dialog presentation segment.