How can Canon 600D (indoor, equipped with two 250W flashlights) shoot clothes to reduce color difference?

The key of LZ color difference is the white balance of flash. If the flash in the camera has no white balance option, LZ can try to operate it manually. Other people's experience seems to be 5500 K-5900 K

Personally, I don't like flash, or it may be because it doesn't work well. . . In my words, I may use a light+white paper to disperse before turning on the light, use a tripod when the light source is not bright enough, and the low ISO+ shutter time is longer. . . Ensure the picture quality. Another advantage of this is that you can manually set the white balance directly with pure white paper.

The lighting layout can be Baidu, there should be, basically left, right and front. The key is to add something like white cloth in front of the lighting to soften it.

Personal opinion, for LZ reference. . .