Admin can set glowing shell on a player using following commands that requiers flag "m"
Additionaly may help you to detect a cheater with wallhack.
amx_red <name or #userid> sets red glowing shell on player.
amx_green <name or #userid> sets green glowing shell on player.
amx_blue <name or #userid> sets blue glowing shell on player.
amx_rgb <name or #userid> sets red, green, blue glowing shell on player.
amx_invis <name or #userid> makes targeted player invisible(cheater with wallhack will see targeted player as visible, and fire in it)
amx_vis <name or #userid> makes player visible or removes glowing shell.
gl
(sorry for mistakes, i'm from kz, don't know English well
)