my smartish_sub {
 my ($colour) = @_;
 
 # Here is the hash with some constants based on the colour.  You can put this hash anywhere really.
 my %colour_indexes = ( 
       red => ( 
            equal_cond => 11,
            button_ind => 1,
            make_colour_ind1 => 1,
            make_colour_ind2 => 2,
               ),
       blue => (
            equal_cond => 1,
            button_ind => -1,
            make_colour_ind1 => -1,
            make_colour_ind2 => -2,
             )
       );

# rest of code is written to use the hash references keyed on the colour, much like moritz described
...