I ran into the same issue. Instead of looking for Glulx extensions that support color, I used bold vs. normal text (where bold indicates an unvisited room and normal text indicates a visited room). Here’s the customization I added to Sand-dancer (Sand Dancer):
VOLUME 7 - ENHANCEMENTS
BOOK 1 - IMPROVED STATUS LINE
[TODO: To view the output from the Property Checking extension, comment this section before the definition of Table of Fancy Status]
When play begins:
clear the screen;
clear only the status line;
leave space;
say "[story title]";
say line break;
say "by [story author]";
say line break;
say "[story headline]";
leave space;
say italic text;
say "[story description]";
say monospaced;
leave space;
say "If you have never played interactive fiction, enter HELP for guidance.";
say paragraph break;
say "Press SPACE to begin.";
wait for the SPACE key;
clear the screen;
leave space;
say normal text;
To leave space:
say paragraph break;
say paragraph break;
Table of Fancy Status
left central right
" Region: [regional area] " "" "[top rose]"
" [if in darkness]Darkness[otherwise]Location: [location][end if]" "" "[middle rose]"
" " "" "[bottom rose]"
"" "" ""
" Locations visited: [number of rooms which are visited]/[number of rooms]" "Talents: [if player holds at least one talent][the list of held talents][otherwise]none[end if]" "Cigarettes: [number of cigarettes enclosed by player]"
To say bold text:
say "[bold type]".
To say normal text:
say "[roman type]".
To say italic text:
say "[italic type]".
To say monospaced:
say "[fixed letter spacing]".
To say rose (way - a direction):
let place be the room way from the location;
if the place is a room, say
"[if the place is unvisited][bold text][way abbreviation][else][normal text][way abbreviation][end if][normal text]";
otherwise say
"[way spacing]";
To say (way - a direction) abbreviation:
choose row with a chosen way of way in the Table of Various Directions;
say abbrev entry.
To say (way - a direction) spacing:
choose row with a chosen way of way in the Table of Various Directions;
say spacing entry.
To say regional area:
if in darkness, rule succeeds;
if location is in Around the Tower, say "Around the Tower";
if location is in Office Interior, say "Office Interior";
Table of Various Directions
chosen way abbrev spacing
up "U " " "
northwest "NW " " "
north " N" " "
northeast " NE" " "
east "E" " "
west "W" " "
southeast " SE" " "
south " S" " "
southwest "SW " " "
down "D " " "
inside " IN " " "
outside " OUT " " "
To say top rose:
say "[rose up][rose northwest][rose north][rose northeast][rose inside] ".
To say middle rose:
say " [rose west] + [rose east] ";
To say bottom rose:
say "[rose down][rose southwest][rose south][rose southeast][rose outside] ".
Rule for constructing the status line:
fill status bar with Table of Fancy Status;
rule succeeds.