Answer:
Both yes and no.
Explanation:
Colour can be used to express emotion within the art piece as well as bring it to life. Colour is also often one of the most exciting components of a painting and a drawing. Lets say, in both figurative and abstract paintings, colour can be used for its decorative beauty, to create mood and to express or arouse and emotion (Blue references sadness/glum, Yellow references to joy/happiness, etc). In nature as well as art, colour has a profound effect on the viewer.
Moreover, I will also say that no colour is not exactly important (but it does tell more about an art piece than one that doesn't sport colour) as pencil/pen drawings can also bring life to an aspect by the features and structure of the elements within.
In the end, this would be your decision to make, and I hope this has helped you in any way :)
