How to tell if two paint colours are different?

[BellaBud]

We have recently moved into our new apartment in Sydney. We had chosen the same paint colour for consistency throughout the apartment (walls, skirting, doors, wardrobe exteriors etc). There are 17 apartments in the block and 95% of owners went with whisper white but we chose Martini 1/4 strength. However, our walls are a cool white that appear to be Martini 1/4 strength, but the rest looks warm and I suspect its whisper white, I have questioned this with the builder and painter but they say its all the same colour (it would be a very expensive exercise to repaint, so its in their best interest that I accept his response). I understand that lighting can make a difference, but it doesn't matter if in direct light, or indirect, lights on/off, open area or hallway, there is a difference in the colour (cool/warm). How can I prove (one way or the other) if the paint colours are different or not? Thanks.

[MitchellMc]

Welcome to the Bunnings Workshop community @BellaBud. It's sensational to have you join us, and congratulations on the new apartment.

If I was in your position, I would head into your closest store and pick up a sample pot of Martini 1/4 strength. Paint it on a square piece of cardboard and tape it in the middle of one of the areas you suspect to be whisper white. It will then be very evident if there is a colour mismatch, and I'm sure after showing the builder the difference, they would be convinced that someone indeed picked up the wrong pail of paint.

Please let me know if you have any questions.

Mitchell