Deleting the miscolored text, then undoing fixes the coloring.
I made a function to dump the stream markers. In the file in question there are lots of them. The following one is one inside a comment where some text is miscolored.
Marker:13742, Start=27452, Color:17, Type:172, Flags0, Flags2=16, Pri=225
What I think are the relevant definitions
const VSMARKERTYPEFLAG_AUTO_REMOVE= 0x10;
VSMARKER_TYPE_PRIORITY_KEYWORDS = 225,
My code
_command listmarkers() name_info(','VSARG2_MACRO|VSARG2_MARK|VSARG2_REQUIRES_EDITORCTL)
{
int list[];
int wid = p_window_id;
wid._StreamMarkerFindList(list, wid, 0, wid.p_buf_size, VSNULLSEEK, 0);
foreach (auto sm in list) {
VSSTREAMMARKERINFO info;
if (_StreamMarkerGet(sm, info) == 0) {
if (info.StartOffset > 27400) {
int flags = _MarkerTypeGetFlags(info.type);
int pri = _MarkerTypeGetPriority(info.type);
say("Marker:"sm", Start="(info.StartOffset)", Color:"(info.ColorIndex)", Type:"(info.type)", Flags"(info.MarkerTypeFlags)", Flags2="flags", Pri="pri);
}
}
}
}