Why 'personalige' 'lyserøde' here, even though the letter is not plural?
When adjectives comes after a definitve article or a possessive pronoun like "his", the adjective(s) should have the plural form.
I hope it will help you
Does 'pink letter' have another meaning other than the literal?
Couldn't "is reading" also work?
It should accept it. If it doesn't then please report it.