def test_is_default_color():
"""Test labels layer default color for None and background
Previously, setting color to just default values would
change color mode to DIRECT and display a black layer.
This test ensures `is_default_color` is
correctly checking against layer defaults, and `color_mode`
is only changed when appropriate.
See
- https://github.com/napari/napari/issues/2479
- https://github.com/napari/napari/issues/2953
"""
data = np.random.randint(20, size=(10, 15))
layer = Labels(data)
# layer gets instantiated with defaults
current_color = layer.color
assert layer._is_default_colors(current_color)
# setting color to default colors doesn't update color mode
layer.color = current_color
assert layer.color_mode == 'auto'
# new colors are not default
new_color = {0: 'white', 1: 'red', 3: 'green'}
assert not layer._is_default_colors(new_color)
# setting the color with non-default colors updates color mode
layer.color = new_color
assert layer.color_mode == 'direct'
