Getting so confused with the color issue. Back a couple questions I pluralized marron: ces chaussures sont marrons...and it was incorrect. Read the comments and I thought I understood. Colors agrees in gender/number if they represent something in real world (e.g. roses, violet). Wait, now getting confused again just thinking about THAT. Basic question here is, why is yellow pluralized in this sentence. Should it not be: mes chaussures sont jaune?
"Jaune" is not a real thing, it is only a color adjective, therefore, it has to agree with the noun.
Whereas "marron" is also a noun meaning "chestnut", therefore it does not agree.
Basically, you always have to make a color adjective agree in gender and number with its preceding noun. UNLESS the color is marron or orange. They are just weird and never change. There ISN'T a good reason, it just is
I just used boots 'cos the hint told me boots or shoes or footwear industry and was marked wrong :(