Camera on iPhone SE 3rd generation: getting accurate color

i recently bought an IPhone SE 3rd generation. I’m an artist and when I try to take photos of paintings the camera on the phone isn’t giving me accurate color and the adjustments don’t work to make them accurate. When taking a picture, the camera is automatically reading it as what it thinks is the best color and all the images are too saturated/vivid and not the colors that are actually there. In my settings I have he camera set to “standard”. Anyone know a fix for this? Or do i need to download another camera app and use that?