Lo he comprobado, lo que funciona en Power 9 es lo siguiente:
Código COBOL:
ENVIRONMENT DIVISION.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 SV-COLOR PIC X(4).
01 SV-COLOR-N REDEFINES SV-COLOR PIC S9(9) COMP-5.
PROCEDURE DIVISION.
MOVE X"FFFF3300" TO SV-COLOR
MOVE SV-COLOR-N TO "BackColor" OF CmText1