For sure it is possible. You could use “image sampler” but I tend to prefer “Import Image” because this one show the image as a mesh in Rhino viewport. Then you could get the color of “pixel” using “Mesh Closest Point” the “Mesh Eval” the get the color.
Then use this color to make a material in Grasshopper. You’ll find some script to make the materials. But adding a lot of materials/color could lead to long time (indeed on my PC).