Resin colour moving away from centre

Hi
I’m a beginner at using resin. I’m using platinum artist resin with Placextre pigment powder and resin dye. Once the resin is cured the colour is pulled away from the centre. Ie. Black with gold flakes goes opaque in the centre. Dark blue into light blue with a white wave looked great when I finished but the next day the white colour had moved to the centre?