TextureSample replace color conditionally weird result

I create a material and import an image as texture and I want to replace those color if (r > 0.45 & g > 0.45 & b > 0.45) with other COLOR B.

I am sure that a lot white part of the image pixel meet the condition however the result is that there only exist a few spots in COLOR B on the final material. I dont why, hope for help.

This is the source image:

This is final result:

This is My BluePrint: