However, within the records for John and Mike, I get all of the colors for John and Mike in the portal: red, blue, orange, etc. I only want to see for John and Mike the portal results for "red."
It depends on the expected result. The “portal result” for red is “red” – or, more to the point, it is the found set of all the people that have that colour assigned, regardless of any additional colour assignments for each individual.
Why is it a problem with the portal displaying those other assignments? Maybe all you want is switch to a layout that is designed as a list and/or doesn't have that portal …?
You can enter the color right in the portal to search.
For example, using your data from the case above, if I enter "Red" in the portal itself after clicking Find, I get John and Mike only.
If you search in the portal table itself, it won't know about the relationship between the two tables.
You can also use SQL that would take advantage of the relationship, like this: