When you select the autofilter, the drop down list is created from the unique data in that column. Is there any way to customize this list, so the changes are permanent

For instance, I might have in one(1) column the following 4 row entries

red, blue, green (all are single cell entries
red, blu
re
blue, gree

I want my drop down list to read

re
blu
gree

instead of

red, blue, green
red, blu
re
blue, green (like normal autofilter dropdown choices

If I chose red from the drop down list, the filter would then search every cell in that column containing "red" . The list of "red" "blue" and "green" will be maintained somewhere on the spreadsheet. Thanks for any help to program this with VBA
-Ron