When running the data assist wizard, you cannot use multiple tables.
You need to create this part by hand using the data assist server behaviors.
in your case, the colors table should be set up like:
then you would have a third table to use as a linking table:
prodColorID - Primary key
prodColorColorID - foreign Key relation to colors.colorID
prodColorProductID foreign Key relation to items.ItemNumber
on the product insert page crated by DataAssist, create a new recordset:
SELECT * FROM colors to return all colors
add a checkbox to the page, and set the checked value to come from the colorID column of the recordset you just createed:
<input name="color" type="checkbox" id="color" value="<?php echo $row_rsName['colorID']; ?>"><?php echo $row_rsName['colorName']; ?>
Then use the Manage relational Table server behavior.