I use Micron markers for all of this. I did an advent calendar, quilted it with white thread and then in the colored places I used the micron markers to color the thread to match. I ironed the top afterwards and 13 years later it is great. I have colored parts of fabrics to enhance the colors and that also worked s I do use the micron a lot. I do have some Fabrico as well, but I generally use the micron because the points are finer. They come in a lot of colors.
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