gown not same color as robe purchased, but appeared to be dark purple but actiually was lilac. The gift was for my mother

The gown pictured appears to be dark purple. I purchased a robe to match. The gown is actually lilac, not dark purple as shown. So the gown and robe set I purchased for my mother does not match. As a care giver for my elderly parents I have no time to send anything back. I wished the gown and robe matched. The shadowline products are expensive and superior. My mother loves them. She would have loved them even more if they had matched.