fact – a thing that is known to be true, especially when it can be proved
Definition HERE
Oxford Learners Dictionary
Adjectives that are facts:
color
“I’m wearing a blue shirt.”
age
“I just bought a 1972 Chevy Impala.”
origin (where someone/something is from)
“French food is my favorite.”
shape
“These sunglasses are round.”
size
“A big dog lives next door.”
We might feel like adjectives that describe the size of something are facts but remember people can have different ideas of adjectives like big and small or tall and short.
Adjectives like this are relative. Relative means that the word has a different meaning or a different level depending on how you compare it. Each person may have a different point of comparison or a different experience to compare it to. So The meaning of adjectives like tall and short are related to, or “relative” to each person.
An exact measurement of course is a fact.
“William is 165cm tall.”
opinion – your feelings or thoughts about somebody/something, rather than a fact
Definition HERE
Oxford Learners Dictionary
Adjectives that are opinions:
cool
terrible
pretty\ugly
good\bad
When we combine fact and opinion adjectives in front of a noun, we put the opinion adjective first and the fact adjective second.
“Richard just bought a cool red car. I’m jealous!”
“I saw some cool round sunglasses at the mall yesterday. They were $300.00!”

Other examples:
“Michelle is wearing a big red hat today, you can’t miss her!”