New Component Proposal

I think it would be handy if we had a component that could exclude a specific color and optionally a color range fr om a source image. This would be useful for creating an alpha when there isn't already alpha info for the image. Such as an image rendered with a white, green, or hot pink background but no alpha. This way we could easily exclude that color and have an accurate alpha made from the image quickly and more easily than I can currently figure out how to. Excluding a range would be helpful wh ere those same images have the background color blended at the edges. That way we could expand or narrow the range as necessary to remove more of the background color and regain our edges more completely and accurately. I've attached a couple of example images I'm trying to do this with currently. So far It's very slow and not very effective. This is made more difficult in my case by the need to have it operate in a diverse enough way that it will work for the many hundreds of other images I would like to achieve this with.

Yes, it would be useful.
It can be used in different ways too. We could, instead of simply deleting a range of color, fill it with a texture or an effect.

It is true, we could use a whole filter for selecting a color, like Chromakey.
And we could repeat it for all colors we want to select.
But, in case we want to select and fill only one or two colors, it may be fine.
In case we want to fill with different textures 4-5 different colors, we should repeat Chromakey inside of our filter 4-5 times. Our filter would become heavy.
Then a single component would be probably a better solution, especially adding the chance to enlarge or restrict the range.

It could be very simple. An easy color picker, with a Center color and a Left and Right control for setting the range. Then the component would have a two inputs, one for the source that we want to modify and one for the filling (that could be alpha, a different color, a texture, etc.

Yeah, the color selection and removal process is tricky. What I discovered is that to get what you want, it is a perceptual issue, that is, what our eye and brain see in the color selection process is not easily translated into a mathematical equation. The way we see is in "areas" and relate colors relative to nearby neighbors and not the whole picture. This makes a color matching algorithm difficult to write. I'm sure that it has been attempted, but I've yet to see a good solution in a filter. Hence the wand and area pickers in Photoshop, GIMP, etc where you end up doing it manually. Blah, blah, blah...