[tools] winetest/build-patterns: Tweak the failure color gradients.

[Francois Gouget]

Start from a 'darker cyan' when we need a lot of colors. Stick to
lighter shades when few colors are needed for better color consistency
and aesthetics.

Signed-off-by: Francois Gouget <fgouget(a)codeweavers.com>
---
 winetest/build-patterns | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/winetest/build-patterns b/winetest/build-patterns
index ea9cd4c1d..fe285cc5b 100755
--- a/winetest/build-patterns
+++ b/winetest/build-patterns
@@ -621,11 +621,6 @@ sub blend($$$)
     return $r;
 }
 
-my @keycolors = ([0, 255, 255], # cyan
-                 [0, 255, 0],   # green
-                 [255, 255, 0], # yellow
-                 [255, 0, 0],   # red
-);
 
 # Use colors to differentiate the set values. Each unique value is assigned
 # a color (in HTML format) picked along a series of gradients passing by the
@@ -633,6 +628,12 @@ my @keycolors = ([0, 255, 255], # cyan
 sub compute_set_colors($)
 {
     my ($set) = @_;
+
+    my @keycolors = ([0, 255, 255], # cyan
+                     [0, 255, 0],   # green
+                     [255, 255, 0], # yellow
+                     [255, 0, 0]);  # red
+
     my @values = sort { $a <=> $b } keys %$set;
     my $count = @values;
     if ($count == 1)
@@ -641,6 +642,10 @@ sub compute_set_colors($)
     }
     else
     {
+        # Start from a 'darker cyan' for increased contrast
+        # when many colors are needed.
+        $keycolors[0] = [0, 179, 179] if ($count > 10);
+
         my $k = 0;
         my ($start, $end) = (-1, 0);
         for (0..$count-1)
-- 
2.20.1