Use colorblind-friendly colors in the scatter plots gallery example (#1013)

Co-authored-by: Michael Grund <[email protected]>

Author: vitorgt

examples/gallery/symbols/scatter.py

@@ -21,7 +21,7 @@
     projection="X10c/10c",
     frame=["xa0.2fg", "ya0.2fg", "WSrt"],
 )
-for color in ["blue", "orange", "green"]:
+for color in ["gray73", "darkorange", "slateblue"]:
     x, y = np.random.rand(2, n)  # random X and Y data in [0,1]
     sizes = np.random.rand(n) * 0.5  # random size [0,0.5], in cm
     # plot data points as circles (style="c"), with different sizes
@@ -32,9 +32,9 @@
         sizes=sizes,
         color=color,
         # Set the legend label,
-        # and set the circle size to be 0.25 cm (+S0.25c) in legend
+        # and set the symbol size to be 0.25 cm (+S0.25c) in legend
         label=f"{color}+S0.25c",
-        transparency=70,  # set transparency level for all symbols
+        transparency=50,  # set transparency level for all symbols
     )
 
 fig.legend(transparency=30)  # set transparency level for legends