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How to color your entire vector in just a few seconds
1. Put all paths that are not connected to anything in another layer just below your lines layer, make invisible.
Make sure your entire vector connects back to itself (like the bottom of the shirt)
2. Duplicate your entire vector and move it to your colors layer. While still selecting all; "Union", and then "Break apart"
3. Delete the "Shell" by zooming in really close to an outside edge and deleting the outside path that goes around the entire vector.
Select all and outset by about 0.1-0.01px
4. Color to your heart's content. (I just used the preset colors to save time)
5. Note: The last pic shows why outsetting by such a small number may be bad. You might need to check the coloring of places that are super thin, although in my entire vector I only found two such places.