Color failure line by result code.

The static red color wouldn't paint skips in their designated yellow.

Use the color name we got from the result label earlier, which marks
skips as yellow.

railties/lib/rails/test_unit/reporter.rb

@@ -33,7 +33,7 @@ def record(result)
       if output_inline? && result.failure && (!result.skipped? || options[:verbose])
         io.puts
         io.puts
-        io.puts format_failures(result).map { |line| color(line, :red) }
+        io.puts format_failures(result).map { |line| color(line, color) }
         io.puts
         io.puts format_rerun_snippet(result)
         io.puts