hell yea these would be gorgeous petpage arts as-is!! if you feel its easier to draw
more pieces if you dont colour them, id say go for it bc people'll love your art whether its coloured or jus lineart :0 (also one cool 'theme' with similar pieces is to do a solid body colour, like gray, but with couple small bits of accent colours (a couple stripes and eyes, for example)
even as lineart, your work imho easily goes to the 50-100m upper range! A++