Hi there,
Yeah, I know the Substance to Unreal texturing has some discrepancies in the way the engines interpret textures. You could try compressing your textures to 8bit RGB instead of 16bit in Photoshop- I’ve used that method in the past to fix color issues.
I would also make sure your Normal texture is sampling properly. Make sure your Compression Settings in the texture are set to Normalmap.
Let me know how this goes! If you’re still encountering issues we can continue troubleshooting.