% scons -Q COLOR=Red foo.o scons: *** Invalid value for option COLOR: Red. Valid values are: ('red', 'green', 'blue') File "/home/my/project/SConstruct", line 5, in <module> % scons -Q COLOR=BLUE foo.o scons: *** Invalid value for option COLOR: BLUE. Valid values are: ('red', 'green', 'blue') File "/home/my/project/SConstruct", line 5, in <module> % scons -Q COLOR=nAvY foo.o scons: *** Invalid value for option COLOR: nAvY. Valid values are: ('red', 'green', 'blue') File "/home/my/project/SConstruct", line 5, in <module>