I've seen some similar posts and I'm not too worried but my blue gourami seems to do that color changing several times a day and it happens very quickly. Other posts I have read seem to indicate this change over long periods of time or like a more permanent event. I believe it's because of temporary overcrowding (platys had fry so my other tank has like 40 babies in it and had to move adults into this tank totaling 8 fish for 20 gal, I know it's bad but not much longer). Water parameters have been same as always and tank was cycled almost a year ago. Also have an overkill filter and frequent water changes. None of the fish have health or behavioral issues, just thought this a little strange with the frequency and speed of color changing. Poor thing will have space again soon though.