I normally have a strong dislike for white outlines but in this case it fits better than the black one, since the black one has a too strong contrast and sticks out more.

You can also try a different color.

I would have to try it myself to know if it looks better without one and I'm too lazy to do that

If you still want to work on it you could make the outline on another layer and turn it on and off to see what you like more.

Thank you :) Do you think it would be better to take the outline completely away or to only have one of the two (white or black)?

cute Cucumber! Not a fan of the outline but otherwise I like it and think it's a nice homage to the low contrast but colorful original style