About colour hex code locking in Paint.NET Discussion and Questions Posted January 10, 2018 · Report reply I want to update something. I caught it. I knew how it happened. I said that the colour changed, this was found when I applied overlay blending. Now I saw it happened again. I am not sure if this is a bug but I will tell you what I saw. I am using a colour with hex code 745A3A. For convenience, I set both primary colour and secondary colour to be this colour but one of them has its value changed. The HSV says that H = 33, S = 50, V = 45. And you can try to reproduce this little error. Add 1 to V, then switch colour by using X, then switch again. It changes from H = 33 to H = 32, V = 46 to V = 45. So what I saw about the overlay blending was not wrong. I am aware of this issue after looking at what Pratyush said. I thought when I use HSV, then changing V should keep H and S the same. After some time of drawing, H = 33 became H = 24. I was aware that the colour becomes more orangeish. I think the H and V shifting was the reason why I thought there was error in the colour palette.