Introduction

Since plotly and pyqtgraph do not have (or few?) Color palettes, it is more difficult to specify colors than matplotlib. This time, I will introduce a module that allows you to easily create color gradations.

environment

Mac OS Python 3.8.5 colour 0.1.5

pip install colour

Details

Create

All will be red.

from colour import Color

Color('red')
Color(red=1)
Color('#f00')
Color('#ff0000')
Color(rgb=(1, 0, 0))  # 0~1
Color(hsl=(0, 1, 0.5))  # 0~1
Color(Color('red'))

Get value

from colour import Color

c = Color('red')  # <class 'colour.Color'>

Gets the value of c.

RGB

rgb = c.get_rgb()  # (1.0, 0.0, 0.0), tuple
rgb_hex = c.get_hex()  # #f00, str
rgb_hex_long = c.get_hex_l()  # #ff0000, str

HSL

hsl = c.get_hsl()  #hsl color space(0.0, 1.0, 0.5), tuple
hue = c.get_hue()  #Hue 0.0, float
saturation = c.get_saturation()  #Saturation 1.0, float
luminance = c.get_luminance()  #Luminance 0.5, float

monochromatic

red = c.get_red()  # 1.0, float
blue = c.get_blue()  # 0.0, float
green = c.get_green()  # 0.0, float

Value change

c = Color('red')  # c = red

Rewrite the value of c

c.set_blue(1)  # c = magenta, set_red(), set_green()There is also
c.set_saturation(0.5)  #Change saturation, c = #bf40bf, 0~Between 1
c.set_luminance(0.2)  #Change brightness, c = #4c194c, 0~Between 1

#The value is overwritten
c.set_rgb((1, 0, 0))
c.set_hsl((0, 1, 0.5))

Judgment

Color('red') == Color('blue')
False
Color('red') == Color('red')
True
Color('red') != Color('blue')
True
Color('red') != Color('red')
False

Gradation

Specify the start color, end color, and the number of divisions

# red -Between blue
red = Color('red')
blue = Color('blue')
#5 divisions[<Color red>, <Color yellow>, <Color lime>, <Color cyan>, <Color blue>]
red_blue = list(red.range_to(blue, 5))

# black -Between white
black = Color('black')
white = Color('white')
#6 divisions[<Color black>, <Color #333>, <Color #666>, <Color #999>, <Color #ccc>, <Color white>]
black_white = list(black.range_to(white, 6))

Example of use

Since matplotlib and seaborn can specify many colors from the beginning, you may not use them much. I think it can be used for plotly.

from colour import Color
import matplotlib.pyplot as plt

fig = plt.figure()
ax = fig.add_subplot(111)

red = Color('red')
blue = Color('blue')
red_blue = list(red.range_to(blue, 100))

for num, color in enumerate(red_blue, 1):
    ax.plot([i for i in range(10)],
            [i * num for i in range(10)],
            c=color.get_hex_l())

plt.show()