The wildmind website does list seeing colours as one of the signs of progress. So you should obviously find that encouraging. However it does caution
But it’s best not to pay much attention to those lights or they will
turn into a distraction and slow your progress.
This accords with my own experience. While various strange things during meditation is fascinating, too much fascination will mean that you are not focusing on whatever your object of meditation actually is (breath, visualisation etc...). Absolutely dig around in them and have a little investigate but ultimately return to the practice you are doing. Just my experience of course.