diff --git a/lib/configure.js b/lib/configure.js
index d50d962..c85a4de 100644
--- a/lib/configure.js
+++ b/lib/configure.js
@@ -154,6 +154,10 @@ module.exports = function(overrides) {
       // Use the appropriate color for the log level.
       var colorMappings = _.isObject(options.colors) ? options.colors : {};
       var colorName = colorMappings[logAt];
+      // Failsafe in case of troublesome configuration:
+      if (colorName === undefined) {
+        colorName = 'white';
+      }
 
       // Get the ANSI-colorized prefix.
       var colorizedPrefix = (function _getColorizedPrefix() {