Looking for excel or google sheet expert

Hi
I am looking to create a formula in google sheet expert that would highlight duplicates.

Problem i need help with
===================

I am creating lots of prompts with chatgpt which i then insert into google sheets to keep track of all my prompts.
But i noticed that often chatgpt recreates the exact same prompts which creates duplicates which i want to avoid

Solution needed
===============
I need a expert in google sheet to create a code that will easily highlight all the duplicates by individual color. Example:

/imagines prompt: apples in a bag
/imagines prompt: car chase
/imagines prompt: cow grassing
/imagines prompt: apples in a bag
/imagines prompt: car chase
/imagines prompt: cow grassing
/imagines prompt: apples in a bag

It formula would show me on google sheets highlighted:

All prompts with the apples in a bag highlighted in red

All promptd with cow grassing highlighted in yellow

All prompts with car chase
highlighted in blue


So with the formula as soon as i input the new prompts into the same sheets , it would highlight the prompts that duplicates which i can then erase

P.s. if you are an excel expert make sure that the formula works well google sheet



Ideal Skills and Experience:
- Proficient in excel or google sheets
- Strong knowledge of creating complex formulas and functions
- Ability to provide advice on suitable functions or formulas for the task
- Efficient and able to meet deadlines