@@ -160,11 +160,11 @@ def demo(sty):
160160# The visual below shows name collisions. Color names where color values agree
161161# are in bold.
162162
163- import matplotlib ._color_data as mcd
163+ import matplotlib .colors as mcolors
164164import matplotlib .patches as mpatch
165165
166- overlap = {name for name in mcd .CSS4_COLORS
167- if " xkcd:" + name in mcd .XKCD_COLORS }
166+ overlap = {name for name in mcolors .CSS4_COLORS
167+ if f' xkcd:{ name } ' in mcolors .XKCD_COLORS }
168168
169169fig = plt .figure (figsize = [9 ,5 ])
170170ax = fig .add_axes ([0 ,0 ,1 ,1 ])
@@ -173,23 +173,30 @@ def demo(sty):
173173n_rows = len (overlap )// n_groups + 1
174174
175175for j ,color_name in enumerate (sorted (overlap )):
176- css4 = mcd .CSS4_COLORS [color_name ]
177- xkcd = mcd .XKCD_COLORS ["xkcd:" + color_name ].upper ()
176+ css4 = mcolors .CSS4_COLORS [color_name ]
177+ xkcd = mcolors .XKCD_COLORS [f'xkcd:{ color_name } ].upper ()
178+
179+ # Pick text colour based on perceived luminance.
180+ rgba = mcolors .to_rgba_array ([css4 ,xkcd ])
181+ luma = 0.299 * rgba [:,0 ]+ 0.587 * rgba [:,1 ]+ 0.114 * rgba [:,2 ]
182+ css4_text_color = 'k' if luma [0 ]> 0.5 else 'w'
183+ xkcd_text_color = 'k' if luma [1 ]> 0.5 else 'w'
178184
179185col_shift = (j // n_rows )* 3
180186y_pos = j % n_rows
181- text_args = dict (va = 'center' ,fontsize = 10 ,
182- weight = 'bold' if css4 == xkcd else None )
187+ text_args = dict (fontsize = 10 ,weight = 'bold' if css4 == xkcd else None )
183188ax .add_patch (mpatch .Rectangle ((0 + col_shift ,y_pos ),1 ,1 ,color = css4 ))
184189ax .add_patch (mpatch .Rectangle ((1 + col_shift ,y_pos ),1 ,1 ,color = xkcd ))
185- ax .text (0 + col_shift ,y_pos + .5 ,' ' + css4 ,alpha = 0.5 ,** text_args )
186- ax .text (1 + col_shift ,y_pos + .5 ,' ' + xkcd ,alpha = 0.5 ,** text_args )
187- ax .text (2 + col_shift ,y_pos + .5 ,' ' + color_name ,** text_args )
190+ ax .text (0.5 + col_shift ,y_pos + .7 ,css4 ,
191+ color = css4_text_color ,ha = 'center' ,** text_args )
192+ ax .text (1.5 + col_shift ,y_pos + .7 ,xkcd ,
193+ color = xkcd_text_color ,ha = 'center' ,** text_args )
194+ ax .text (2 + col_shift ,y_pos + .7 ,f'{ color_name } ,** text_args )
188195
189196for g in range (n_groups ):
190197ax .hlines (range (n_rows ),3 * g ,3 * g + 2.8 ,color = '0.7' ,linewidth = 1 )
191- ax .text (0.5 + 3 * g ,- 0.5 ,'X11' ,ha = 'center' , va = 'center' )
192- ax .text (1.5 + 3 * g ,- 0.5 ,'xkcd' ,ha = 'center' , va = 'center' )
198+ ax .text (0.5 + 3 * g ,- 0.3 ,'X11/CSS4 ' ,ha = 'center' )
199+ ax .text (1.5 + 3 * g ,- 0.3 ,'xkcd' ,ha = 'center' )
193200
194201ax .set_xlim (0 ,3 * n_groups )
195202ax .set_ylim (n_rows ,- 1 )