如何设置'REUSE_ALV_GRID_DISPLAY'的单个单元格的颜色

REPORT  ydemo_rick_a .
TYPE-POOLS: slis.
DATA: BEGIN OF it_flight OCCURS 0,
carrid  LIKE sflight-carrid,
connid   LIKE sflight-connid,
fldate   LIKE sflight-fldate,
seatsmax LIKE sflight-seatsmax,
seatsocc LIKE sflight-seatsocc,
color TYPE lvc_t_scol,
END OF it_flight.
DATA: it_fieldcat TYPE  slis_t_fieldcat_alv,
layout TYPE  slis_layout_alv.
CALL FUNCTION 'REUSE_ALV_FIELDCATALOG_MERGE'
EXPORTING
i_program_name         = sy-repid
i_internal_tabname     = 'IT_FLIGHT'
i_inclname             = sy-repid
CHANGING
ct_fieldcat            = it_fieldcat
EXCEPTIONS
inconsistent_interface = 1
program_error          = 2.
SELECT  carrid
connid
fldate
seatsmax
seatsocc
FROM sflight
INTO CORRESPONDING FIELDS OF TABLE it_flight
UP TO 20 ROWS.
DATA: col TYPE lvc_s_scol,
coltab TYPE lvc_t_scol,
color TYPE lvc_s_colo.
color-col = '6'.
color-int = '0'.
color-inv = '0'.
LOOP AT it_flight.
IF it_flight-seatsocc EQ 0.
col-fname = 'SEATSOCC'.
col-color = color.
APPEND col TO coltab.
CLEAR col.
it_flight-color = coltab.
MODIFY  it_flight.
ENDIF.
ENDLOOP.
layout-coltab_fieldname = 'COLOR'.
CALL FUNCTION 'REUSE_ALV_GRID_DISPLAY'
EXPORTING
i_callback_program = sy-repid
is_layout          = layout
it_fieldcat        = it_fieldcat
TABLES
t_outtab           = it_flight
EXCEPTIONS
program_error      = 1.