Python version
n/a

Django version
n/a

Package version
0.10.0

Current behavior (bug description)
The recently added feature for RGB & RGBA doesn't work with the image_field feature. Issue noted #151 (comment)

I realized just now that RGB and RGBA formats raise an error when the image_field option is used: https://github.com/fabiocaccamo/django-colorfield#image_field

This happens because the color returned by get_image_background_color (https://github.com/fabiocaccamo/django-colorfield/blob/main/colorfield/utils.py#L4) is always in HEX / HEXA format.

Expected behavior
RGB/RGBA format should work with image_field.