Adding a character before certain words in a column

Hey, I'm pretty new to macros, its time I finally posted because I can't find a solution anywhere.

I have a list of keywords in column F, for example

black green blue
yellow red pink
orange silver black

I would like to make a macro which turns that list of keywords into

black +green +blue
+yellow +red +pink
+orange +silver black

(in this case Ive chosen to exclude the word black)

Any ideas? too many entries to do manually. Thanks!

Hello M'
Try this
=if(or(f1=green,f1=blue,f1=yellow,f1=red,f1=pink,f1=orange,f1=silver)=true,"+"&f1,f1)
Then copy down cells

Regards
Peter