Though only the last verse mentions wearing red, here's the complete lyrics to "Casey Jones" as found in Dorothy Scarborough's 1925 book "On The Trail Of Negro Folk Songs" :

CASEY JONES
Casey Jones was engineer;
Told his fireman not to fear,
All he wanted was boiler hot;
Run in Canton 'bout four o'clock.

One Sunday mornin' it was drizzlin' rain;
Looked down de road an' saw a train,
Foreman says, "Let's make a jump;
Two locomotives an' dey bound to bump."

Casey Jones, I know him well,
Tol' de fireman to ring de bell,
Fireman jump an' say "Goodbye,
Casey Jones, you're bound to die,"

Went down to de depot track,
Begging my honey to take me back;
She turn round some two or three times-
"Take you back when you learn to grind."

Womens in Kansas all dressed in red,
Got de news dat Casey was dead.
Womens in Kansas all dressed in black,
Said,in fact, he was a crackerjack.

[p. 250; Folklore Associates Edition; 1963]