I think the main problem is that you normalize the mouse position in 'Get Mouse Position', while setting the space in 'Raycast' to be local ("Self"). If you normalize any screen related measurement, you convert it from local space to view port space (wich is the current point on the screen in relation to the corners, a.k.a. bottom left is 0,0 | top left is 1,1 | middle of the screen is 0.5,0.5). So if you untick that, both actions should be in local space.
I've also read on a similar problem, that Unity flips textures on the y axis internally and I doubt that 'Get Pixel Color' has taken that into account, so you might need to invert the "Int_TextureCoord_Y" variable before 'Get Pixel Color' (by using 'Int Operator' and multiplying with -1).
Also you haven't set a GameObject in your 'Raycast' action. I assume you'd need to set the camera that can display the texture in there and make sure that it is in front of the texture, otherwise you'd have to flip the z-direction.
That 'Get Pixel Color' requires int variables is actually correct, because it uses the pixel of the texture to determine the current position, which are expressed in natural numbers.
In general I'd suggest that you enable Debug-mode (at the bottom of the 'State'-tab next to "Hide unused"), then you can see all the runtime values of set variables, which makes it easier to see on which action it starts to give an unexpected result.
I could also imagine that the 'Get Raycast Hit Info Extras' action is either not the right choice for this endeavor or doesn't work correctly.
