python - Darken or lighten a color in matplotlib -

say have color in matplotlib. maybe it's string ('k') or rgb tuple ((0.5, 0.1, 0.8)) or hex (#05fa2b). there command / convenience function in matplotlib allow me darken (or lighten) color.

i.e. there matplotlib.pyplot.darken(c, 0.1) or that? guess i'm hoping that, behind scenes, take color, convert hsl, either multiply l value given factor (flooring @ 0 , capping @ 1) or explicitly set l value given value , return modified color.

a few months ago had solve problem. idea user choose color (any color) , software automatically generated colormap (this part of package scientific purposes).

in case here code used achieve it. won't need of object give ask:

import math  class color():     def __init__(self, color, fmt='rgb'):         self.__initialize__(color, fmt)      def __initialize__(self, color, fmt='rgb'):         if fmt == 'rgb':             self.rgb = (int(color[0]), int(color[1]), int(color[2]))             self.hex = self._rgb2hex(self.rgb)             self.hsv = self._rgb2hsv(self.rgb)             self.rgb0 = self.rgb[0] / 255, self.rgb[1] / 255, self.rgb[2] / 255         elif fmt == 'rgb0':             self.rgb = (int(color[0] * 255), int(color[1] * 255), int(color[2] * 255))             self.hex = self._rgb2hex(self.rgb)             self.hsv = self._rgb2hsv(self.rgb)             self.rgb0 = (color[0], color[1], color[2])         elif fmt == 'hex':             self.hex = color             self.rgb = self._hex2rgb(self.hex)             self.hsv = self._rgb2hsv(self.rgb)             self.rgb0 = self.rgb[0] / 255, self.rgb[1] / 255, self.rgb[2] / 255         elif fmt == 'hsv':             self.hsv = color             self.rgb = self._hsv2rgb(self.hsv)             self.hex = self._rgb2hex(self.rgb)             self.rgb0 = self.rgb[0] / 255, self.rgb[1] / 255, self.rgb[2] / 255         self.__automaticpalette__()      def __automaticpalette__(self):         self.rgbcolors = []         self.hexcolors = []         self.hsvcolors = []         self.rgb0colors = []         hsv = self.hsv         in range(255):             new_hsv = hsv[0], hsv[1], (1 / 255) *             self.rgbcolors.append(self._hsv2rgb(new_hsv))             self.hexcolors.append(self._rgb2hex(self.rgbcolors[-1]))             self.hsvcolors.append(new_hsv)             r, g, b = self.rgbcolors[-1]             self.rgb0colors.append((r / 255, g / 255, b / 255))      def _testpalette(self, o=1):         matplotlib import pyplot plt         matplotlib.patches import rectangle         if o == 1:             somex, somey = 0.5, 0.1             plt.figure()             s = 1             currentaxis = plt.gca()             x in range(254):                 currentaxis.add_patch(rectangle((x * s, somey), s, 0.1, alpha=1, color=self.rgb0colors[x]))             currentaxis.add_patch(rectangle((5 * s, somey + 0.07), 30, 0.02, alpha=1, color=self.rgb0))              plt.ylim(0.1, 0.2)             plt.xlim(0, (x + 1) * s)             plt.show()         elif o == 2:             local = self.rgb0colors[90:190][0:-1:10]             somex, somey = 0.5, 0.1             plt.figure()             s = 1             currentaxis = plt.gca()             x in range(len(local)):                 currentaxis.add_patch(rectangle((x * s, somey), s, 0.1, alpha=1, color=local[x]))             currentaxis.add_patch(rectangle((5 * s, somey + 0.07), 30, 0.02, alpha=1, color=self.rgb0))              plt.ylim(0.1, 0.2)             plt.xlim(0, (x + 1) * s)             plt.show()      def _hex2rgb(self, value):         # http://stackoverflow.com/questions/214359/converting-hex-color-to-rgb-and-vice-versa         value = value.lstrip('#')         lv = len(value)         return tuple(int(value[i:i + int(lv / 3)], 16) in range(0, lv, int(lv / 3)))      def _rgb2hex(self, rgb):         # http://stackoverflow.com/questions/214359/converting-hex-color-to-rgb-and-vice-versa         r = rgb[0]         g = rgb[1]         b = rgb[2]         return '#%02x%02x%02x' % (r, g, b)      def _hsv2rgb(self, hsv):         # http://code.activestate.com/recipes/576919-python-rgb-and-hsv-conversion/         h, s, v = hsv         h = float(h)         s = float(s)         v = float(v)         h60 = h / 60.0         h60f = math.floor(h60)         hi = int(h60f) % 6         f = h60 - h60f         p = v * (1 - s)         q = v * (1 - f * s)         t = v * (1 - (1 - f) * s)         r, g, b = 0, 0, 0         if hi == 0:             r, g, b = v, t, p         elif hi == 1:             r, g, b = q, v, p         elif hi == 2:             r, g, b = p, v, t         elif hi == 3:             r, g, b = p, q, v         elif hi == 4:             r, g, b = t, p, v         elif hi == 5:             r, g, b = v, p, q         r, g, b = int(r * 255), int(g * 255), int(b * 255)         return r, g, b      def _rgb2hsv(self, rgb):         # http://code.activestate.com/recipes/576919-python-rgb-and-hsv-conversion/         r, g, b = rgb         r, g, b = r / 255.0, g / 255.0, b / 255.0         mx = max(r, g, b)         mn = min(r, g, b)         df = mx - mn         if mx == mn:             h = 0         elif mx == r:             h = (60 * ((g - b) / df) + 360) % 360         elif mx == g:             h = (60 * ((b - r) / df) + 120) % 360         elif mx == b:             h = (60 * ((r - g) / df) + 240) % 360         if mx == 0:             s = 0         else:             s = df / mx         v = mx         return h, s, v      def getcolor(self, fmt='rgb'):         if fmt == 'rgb':             return self.rgb         elif fmt == 'hex':             return self.hex         elif fmt == 'rgb0':             return self.rgb0         elif fmt == 'hsv':             return self.hsv 

so if call this:

c = color((51, 153, 255)) # c = color((0.5, 0.1, 0.8), fmt='rgb0') # should work rgb0 # c = color('#05d4fa', fmt='hex')        # , hex don't remember if tested careful (the conversions might messy). c._testpalette(1) print(c.rgbcolors) 

it return this:

, , this:

[(0, 0, 0), (0, 0, 1), (0, 1, 2), (0, 1, 3), (0, 2, 4), (0, 3, 5), (1, 3, 6), (1, 4, 7), (1, 4, 8), (1, 5, 9), (1, 6, 10), (2, 6, 11), (2, 7, 12), (2, 7, 13), (2, 8, 14), (2, 9, 15), (3, 9, 16), (3, 10, 17), (3, 10, 18), (3, 11, 19), (3, 12, 20), (4, 12, 21), (4, 13, 22), (4, 13, 23), (4, 14, 24), (4, 15, 25), (5, 15, 26), (5, 16, 27), (5, 16, 28), (5, 17, 29), (5, 18, 30), (6, 18, 31), (6, 19, 32), (6, 19, 32), (6, 20, 34), (6, 21, 35), (7, 21, 36), (7, 22, 36), (7, 22, 38), (7, 23, 39), (7, 24, 40), (8, 24, 40), (8, 25, 42), (8, 25, 43), (8, 26, 44), (8, 26, 44), (9, 27, 46), (9, 28, 47), (9, 28, 48), (9, 29, 48), (9, 30, 50), (10, 30, 51), (10, 31, 52), (10, 31, 52), (10, 32, 54), (10, 33, 55), (11, 33, 56), (11, 34, 56), (11, 34, 58), (11, 35, 59), (11, 36, 60), (12, 36, 60), (12, 37, 62), (12, 37, 63), (12, 38, 64), (12, 38, 65), (13, 39, 65), (13, 40, 67), (13, 40, 68), (13, 41, 69), (13, 42, 70), (14, 42, 71), (14, 43, 72), (14, 43, 73), (14, 44, 73), (14, 45, 75), (15, 45, 76), (15, 46, 77), (15, 46, 78), (15, 47, 79), (15, 48, 80), (16, 48, 81), (16, 49, 81), (16, 49, 83), (16, 50, 84), (16, 50, 85), (17, 51, 86), (17, 52, 87), (17, 52, 88), (17, 53, 89), (17, 53, 89), (18, 54, 91), (18, 55, 92), (18, 55, 93), (18, 56, 94), (18, 57, 95), (19, 57, 96), (19, 58, 97), (19, 58, 97), (19, 59, 99), (19, 60, 100), (20, 60, 101), (20, 61, 102), (20, 61, 103), (20, 62, 104), (20, 62, 105), (21, 63, 105), (21, 64, 107), (21, 64, 108), (21, 65, 109), (21, 66, 110), (22, 66, 111), (22, 67, 112), (22, 67, 113), (22, 68, 113), (22, 69, 115), (23, 69, 116), (23, 70, 117), (23, 70, 118), (23, 71, 119), (23, 72, 120), (24, 72, 121), (24, 73, 121), (24, 73, 123), (24, 74, 124), (24, 74, 125), (25, 75, 126), (25, 76, 127), (25, 76, 128), (25, 77, 129), (25, 77, 130), (26, 78, 131), (26, 79, 131), (26, 79, 133), (26, 80, 134), (26, 81, 135), (27, 81, 136), (27, 82, 137), (27, 82, 138), (27, 83, 139), (27, 84, 140), (28, 84, 141), (28, 85, 142), (28, 85, 143), (28, 86, 144), (28, 86, 145), (29, 87, 146), (29, 88, 147), (29, 88, 147), (29, 89, 149), (29, 90, 150), (30, 90, 151), (30, 91, 152), (30, 91, 153), (30, 92, 154), (30, 93, 155), (31, 93, 156), (31, 94, 157), (31, 94, 158), (31, 95, 159), (31, 96, 160), (32, 96, 161), (32, 97, 162), (32, 97, 163), (32, 98, 163), (32, 99, 165), (33, 99, 166), (33, 100, 167), (33, 100, 168), (33, 101, 169), (33, 101, 170), (34, 102, 171), (34, 103, 172), (34, 103, 173), (34, 104, 174), (34, 105, 175), (35, 105, 176), (35, 106, 177), (35, 106, 178), (35, 107, 179), (35, 107, 179), (36, 108, 181), (36, 109, 182), (36, 109, 183), (36, 110, 184), (36, 110, 185), (37, 111, 186), (37, 112, 187), (37, 112, 188), (37, 113, 189), (37, 114, 190), (38, 114, 191), (38, 115, 192), (38, 115, 193), (38, 116, 194), (38, 116, 195), (39, 117, 195), (39, 118, 197), (39, 118, 198), (39, 119, 199), (39, 120, 200), (40, 120, 201), (40, 121, 202), (40, 121, 203), (40, 122, 204), (40, 123, 205), (41, 123, 206), (41, 124, 207), (41, 124, 208), (41, 125, 209), (41, 125, 210), (42, 126, 211), (42, 127, 211), (42, 127, 213), (42, 128, 214), (42, 129, 215), (43, 129, 216), (43, 130, 217), (43, 130, 218), (43, 131, 219), (43, 132, 220), (44, 132, 221), (44, 133, 222), (44, 133, 223), (44, 134, 224), (44, 135, 225), (45, 135, 226), (45, 136, 227), (45, 136, 227), (45, 137, 229), (45, 138, 230), (46, 138, 231), (46, 139, 232), (46, 139, 233), (46, 140, 234), (46, 140, 235), (47, 141, 236), (47, 142, 237), (47, 142, 238), (47, 143, 239), (47, 144, 240), (48, 144, 241), (48, 145, 242), (48, 145, 243), (48, 146, 243), (48, 147, 245), (49, 147, 246), (49, 148, 247), (49, 148, 248), (49, 149, 249), (49, 149, 250), (50, 150, 251), (50, 151, 252), (50, 151, 253), (50, 152, 254)] 

which list of color generated create color map. it's custom though, matplotlib used plot it.

edit: note explain how achieved. rgb gives value red, green , blue. hsl (hsv) on other hand gives hue, saturation, , lightness (value). if convert color rgb hsl , run whole spectrum of lightness you'll obtain dark light values of color (for example blue remain blue, although lighter , darker).