For the crosses, I made the seeds of the crosses but normally if you want to develop something like this if you put 3 seeds with at least one different one, you can make 24 combinations
to see afterwards how you want to do

S  I  R     = W W
R  I  S     = W B

S  R  R     = W R
R  R  S     = W G

S  S  R     = W Y
R  S  S     = B W
------------------
I  I  R     = B B
R  I  I     = B R

I  R  R     = B G
R  R  I     = B Y

I  S  R     = R W
R  S  I     = R B
-----------------

I  I  S     = R R
S  I  I     = Y Y

I  R  S     = R Y
S  R  I     = Y W

I  S  S     = Y B
S  S  I     = Y R

-----------------

S  I  S     = Y G
S  R  S     = R G

R  I  R     = G W
R  S  R     = G B

I  S  I     = G R
I  R  I     = G Y

All same seed      = G G