diff --git a/tests/basic-test.js b/tests/basic-test.js
index 4cabf1a..8ffb149 100644
--- a/tests/basic-test.js
+++ b/tests/basic-test.js
@@ -61,3 +61,13 @@ assert.equal(typeof ('astring'.red), 'string');
 assert.equal(typeof ('astring'.error), 'string');
 
 assert.equal(s, 'string');
+
+colors.setTheme({custom: ['blue', 'bold', 'underline']});
+assert.equal(colors.custom(s),
+  '\x1b[34m' + '\x1b[1m' + '\x1b[4m' + s +
+  '\x1b[24m' + '\x1b[22m' + '\x1b[39m' );
+
+colors.setTheme({custom: ['red', 'italic', 'inverse']});
+assert.equal(colors.custom(s),
+  '\x1b[31m' + '\x1b[3m' + '\x1b[7m' + s +
+  '\x1b[27m' + '\x1b[23m' + '\x1b[39m' );
\ No newline at end of file
diff --git a/tests/safe-test.js b/tests/safe-test.js
index db886eb..b2a091c 100644
--- a/tests/safe-test.js
+++ b/tests/safe-test.js
@@ -57,3 +57,12 @@ colors.setTheme({error: 'red'});
 assert.equal(typeof (colors.red('astring')), 'string');
 assert.equal(typeof (colors.error('astring')), 'string');
 
+colors.setTheme({custom: ['blue', 'bold', 'underline']});
+assert.equal(colors.custom(s),
+  '\x1b[4m' + '\x1b[1m' + '\x1b[34m' + s +
+  '\x1b[39m' + '\x1b[22m' + '\x1b[24m' );
+
+colors.setTheme({custom: ['red', 'italic', 'inverse']});
+assert.equal(colors.custom(s),
+  '\x1b[7m' + '\x1b[3m' + '\x1b[31m' + s +
+  '\x1b[39m' + '\x1b[23m' + '\x1b[27m' );