How to extract tags from a reference image in Earth Engine?

let's say, I have an image of a region and each value between 0 and 255 has a different color and represents a category, such as: 0 = corn, 1 = soy, 2 = rice, etc. Each value has a different palette color, 0 = blue, 1 = green, etc.

I now have a satellite image of that scene, and I want to determine which pixels correspond to each pixel in the reference image that I mentioned earlier, for example, I want a list of lat, lon of all blue pixels that are of value 0 and represent corn , so I can say where that pixel will fall on my raw image.

Earth Engine does not provide an API to manipulate images at the pixel level, or if there is such a thing, it is not simple and obvious to me how I should do it, it does not even provide an indexing API in the image collection to access different images one by one ! It is confusing for me.

What is the general and direct way to extract a list of lat, lon of desired pixel values ​​in Earth Engine?