Its an easy solution , create a referane characterstic and read the sales order material.
Create your dependency comparing the referance characterstic and use it in syntax like below.
to know more on referance characteristic you can use link. Reference Characteristics - Characteristics (CA-CL-CHR) - SAP Library
ex. create REF_MATNR referance characteristic for material refering to table -filed VBAP-MATNR
Characteristic for colour = COLOUR
write syntax like below
$SELF.COLOUR = 'Voilet' or 'Indigo' or 'Blue' if $SELF.REF_MATNR = 'M1'
Give it a try and i am sure it will work for you.
Thanks
Ritesh