As what you already know, adjectives are words that describe (or modify) a noun. It tells you something extra about that noun. In addition to that, more than one adjective could be used before a noun. However, the additional adjectives need to be arranged in order.
Do you know why we say:
“The clear blue sea.” (√), and not “The blue clear sea.” (X)?
That’s because when you want to use more than one adjective preceding a noun, you need to follow the Opshacom rule. Here’s what the opshacom rule means:
Opinion: clear, good, useful
Shape: big, fat, long, round
Age: old, new, young
Colour: blue, black, yellowish
Origin: Italian, ancient, western
Material: wooden, metal, paper, cotton
By looking at the opshacom rule, do you know why “The clear blue sea.” is correct?
The clear (opinion) blue (colour) sea.
In the opshacom rule, opinion comes before colour, so the order of adjectives is correct. This makes the sentence correct, too.