diff --git a/driver.py b/driver.py
index 19f8d06..1af6201 100755
--- a/driver.py
+++ b/driver.py
@@ -55,7 +55,7 @@ def load_relations():
             # Naming the relation
             relname = i[:-4]
 
-            print ("Loading relation %s with name %s..." % (i, relname))
+            print("Loading relation %s with name %s..." % (i, relname))
 
             rels[relname] = relation.Relation.load_csv('%s%s' % (examples_path, i))
             print('done')
@@ -102,45 +102,45 @@ def execute_tests():
             else:
                 f_bad += 1
 
-    print (colorize("Resume of the results", COLOR_CYAN))
+    print(colorize("Resume of the results", COLOR_CYAN))
 
-    print (colorize("Query tests", COLOR_MAGENTA))
-    print ("Total test count: %d" % q_tot)
-    print ("Passed tests: %d" % q_good)
+    print(colorize("Query tests", COLOR_MAGENTA))
+    print("Total test count: %d" % q_tot)
+    print("Passed tests: %d" % q_good)
     if q_bad > 0:
-        print (colorize("Failed tests count: %d" % q_bad, COLOR_RED))
+        print(colorize("Failed tests count: %d" % q_bad, COLOR_RED))
 
-    print (colorize("Python tests", COLOR_MAGENTA))
-    print ("Total test count: %d" % py_tot)
-    print ("Passed tests: %d" % py_good)
+    print(colorize("Python tests", COLOR_MAGENTA))
+    print("Total test count: %d" % py_tot)
+    print("Passed tests: %d" % py_good)
     if py_bad > 0:
-        print (colorize("Failed tests count: %d" % py_bad, COLOR_RED))
+        print(colorize("Failed tests count: %d" % py_bad, COLOR_RED))
 
-    print (colorize("Execute Python tests", COLOR_MAGENTA))
-    print ("Total test count: %d" % ex_tot)
-    print ("Passed tests: %d" % ex_good)
+    print(colorize("Execute Python tests", COLOR_MAGENTA))
+    print("Total test count: %d" % ex_tot)
+    print("Passed tests: %d" % ex_good)
     if ex_bad > 0:
-        print (colorize("Failed tests count: %d" % ex_bad, COLOR_RED))
+        print(colorize("Failed tests count: %d" % ex_bad, COLOR_RED))
 
-    print (colorize("Execute fail tests", COLOR_MAGENTA))
-    print ("Total test count: %d" % f_tot)
-    print ("Passed tests: %d" % f_good)
+    print(colorize("Execute fail tests", COLOR_MAGENTA))
+    print("Total test count: %d" % f_tot)
+    print("Passed tests: %d" % f_good)
     if f_bad > 0:
-        print (colorize("Failed tests count: %d" % f_bad, COLOR_RED))
+        print(colorize("Failed tests count: %d" % f_bad, COLOR_RED))
 
-    print (colorize("Total results", COLOR_CYAN))
+    print(colorize("Total results", COLOR_CYAN))
     if f_bad + q_bad + py_bad + ex_bad == 0:
-        print (colorize("No failed tests", COLOR_GREEN))
+        print(colorize("No failed tests", COLOR_GREEN))
         return 0
     else:
-        print (colorize("There are %d failed tests" %
+        print(colorize("There are %d failed tests" %
                (f_bad + py_bad + q_bad + ex_bad), COLOR_RED))
         return 1
 
 
 def run_exec_test(testname):
     '''Runs a python test, which executes code directly rather than queries'''
-    print ("Running python test: " + colorize(testname, COLOR_MAGENTA))
+    print("Running python test: " + colorize(testname, COLOR_MAGENTA))
 
     glob = rels.copy()
     exp_result = {}
@@ -149,19 +149,19 @@ def run_exec_test(testname):
 
     try:
         exec(expr, glob)  # Evaluating the expression
-        print (colorize('Test passed', COLOR_GREEN))
+        print(colorize('Test passed', COLOR_GREEN))
         return True
     except Exception as e:
-        print (colorize('ERROR', COLOR_RED))
-        print (colorize('=====================================', COLOR_RED))
+        print(colorize('ERROR', COLOR_RED))
+        print(colorize('=====================================', COLOR_RED))
         traceback.print_exc(file=sys.stdout)
-        print (colorize('=====================================', COLOR_RED))
+        print(colorize('=====================================', COLOR_RED))
         return False
 
 
 def run_py_test(testname):
     '''Runs a python test, which evaluates expressions directly rather than queries'''
-    print ("Running expression python test: " +
+    print("Running expression python test: " +
            colorize(testname, COLOR_MAGENTA))
     exp_result = None
     result = None
@@ -174,21 +174,21 @@ def run_py_test(testname):
         exp_result = eval(expr, rels)
 
         if result == exp_result:
-            print (colorize('Test passed', COLOR_GREEN))
+            print(colorize('Test passed', COLOR_GREEN))
             return True
     except:
         pass
 
-    print (colorize('ERROR', COLOR_RED))
-    print (colorize('=====================================', COLOR_RED))
-    print ("Expected %s" % exp_result)
-    print ("Got %s" % result)
-    print (colorize('=====================================', COLOR_RED))
+    print(colorize('ERROR', COLOR_RED))
+    print(colorize('=====================================', COLOR_RED))
+    print("Expected %s" % exp_result.pretty_string(tty=True))
+    print("Got %s" % result.pretty_string(tty=True))
+    print(colorize('=====================================', COLOR_RED))
     return False
 
 def run_fail_test(testname):
     '''Runs a test, which executes a query that is supposed to fail'''
-    print ("Running fail test: " + colorize(testname, COLOR_MAGENTA))
+    print("Running fail test: " + colorize(testname, COLOR_MAGENTA))
 
     query = readfile('%s%s.fail' % (tests_path, testname)).strip()
     test_succeed = True
@@ -216,9 +216,9 @@ def run_fail_test(testname):
         pass
 
     if test_succeed:
-        print (colorize('Test passed', COLOR_GREEN))
+        print(colorize('Test passed', COLOR_GREEN))
     else:
-        print (colorize('Test failed (by not raising any exception)', COLOR_RED))
+        print(colorize('Test failed (by not raising any exception)', COLOR_RED))
     return test_succeed
 
 def run_test(testname):
@@ -228,7 +228,7 @@ def run_test(testname):
     testname.result
     The query will be executed both unoptimized and
     optimized'''
-    print ("Running test: " + colorize(testname, COLOR_MAGENTA))
+    print("Running test: " + colorize(testname, COLOR_MAGENTA))
 
     query = None
     expr = None
@@ -254,32 +254,32 @@ def run_test(testname):
         c_result = eval(c_expr, rels)
 
         if (o_result == result_rel) and (result == result_rel) and (c_result == result_rel):
-            print (colorize('Test passed', COLOR_GREEN))
+            print(colorize('Test passed', COLOR_GREEN))
             return True
     except Exception as inst:
         traceback.print_exc(file=sys.stdout)
-        print (inst)
+        print(inst)
         pass
-    print (colorize('ERROR', COLOR_RED))
-    print ("Query: %s -> %s" % (query, expr))
-    print ("Optimized query: %s -> %s" % (o_query, o_expr))
-    print (colorize('=====================================', COLOR_RED))
-    print (colorize("Expected result", COLOR_GREEN))
-    print (result_rel)
-    print (colorize("Result", COLOR_RED))
-    print (result)
-    print (colorize("Optimized result", COLOR_RED))
-    print (o_result)
-    print (colorize("optimized result match %s" %
+    print(colorize('ERROR', COLOR_RED))
+    print("Query: %s -> %s" % (query, expr))
+    print("Optimized query: %s -> %s" % (o_query, o_expr))
+    print(colorize('=====================================', COLOR_RED))
+    print(colorize("Expected result", COLOR_GREEN))
+    print(result_rel.pretty_string(tty=True))
+    print(colorize("Result", COLOR_RED))
+    print(result.pretty_string(tty=True))
+    print(colorize("Optimized result", COLOR_RED))
+    print(o_result.pretty_string(tty=True))
+    print(colorize("optimized result match %s" %
            str(result_rel == o_result), COLOR_MAGENTA))
-    print (colorize("result match %s" %
+    print(colorize("result match %s" %
            str(result == result_rel), COLOR_MAGENTA))
-    print (colorize('=====================================', COLOR_RED))
+    print(colorize('=====================================', COLOR_RED))
     return False
 
 
 if __name__ == '__main__':
-    print ("-> Starting testsuite for relational")
+    print("-> Starting testsuite for relational")
     load_relations()
-    print ("-> Starting tests")
+    print("-> Starting tests")
     exit(execute_tests())
diff --git a/relational/relation.py b/relational/relation.py
index 6ec03d2..4524834 100644
--- a/relational/relation.py
+++ b/relational/relation.py
@@ -412,22 +412,49 @@ class Relation:
     def __len__(self):
         return len(self.content)
 
-    def __str__(self):
-        m_len = [len(i) for i in self.header]  # Maximum lenght string
+    def __str__(self) -> str:
+        return self.pretty_string(tty=False)
+
+    def pretty_string(self, tty: bool) -> str:
+        '''
+        Returns a printable string.
+
+        If tty is enabled, it will attempt to add ANSI color codes
+        '''
+        c = lambda i, ansi: i
+        if not tty:
+            colorize = c
+        else:
+            from os import isatty
+            if isatty(1) and isatty(2):
+                try:
+                    from xtermcolor import colorize  # type: ignore
+                except ModuleNotFoundError:
+                    colorize = c
+            else:
+                colorize = c
+        m_len = [len(i) + 2 for i in self.header]  # Maximum lenght string
 
         for f in self.content:
-            for col, i in enumerate(str(val) for val in f):
-                if len(i) > m_len[col]:
-                    m_len[col] = len(i)
+            for col, k in enumerate(str(val) for val in f):
+                if len(k) + 2 > m_len[col]:
+                    m_len[col] = len(k) + 2
 
         res = ""
-        for f, attr in enumerate(self.header):
-            res += attr.ljust(2 + m_len[f])
+        for j, attr in enumerate(self.header):
+            res += colorize(attr.ljust(m_len[j]), ansi=3)
 
         for r in self.content:
             res += "\n"
-            for col, i in enumerate(str(val) for val in r):
-                res += i.ljust(2 + m_len[col])
+            for col, i in enumerate(r):
+                cell = str(i).ljust(m_len[col])
+                if isinstance(i, (int, float)):
+                    cell = colorize(cell, ansi=4)
+                elif i is None:
+                    cell = colorize(cell, ansi=1)
+                elif not isinstance(i, str):
+                    cell = colorize(cell, ansi=15)
+                res += cell
 
         return res
 
diff --git a/relational_readline/linegui.py b/relational_readline/linegui.py
index 6471bc3..fea09cb 100644
--- a/relational_readline/linegui.py
+++ b/relational_readline/linegui.py
@@ -165,12 +165,19 @@ def help(command: str) -> None:
     p = command.split(' ', 1)
     if len(p) == 1:
         print(
-            'HELP command\n'
+            'HELP [command]\n'
+            '\n'
+            'Comments are obtained starting with a ;\n'
+            '\n'
             'To execute a query:\n'
             '[relation =] query\n'
+            '\n'
             'If the 1st part is omitted, the result will be stored in the relation last_.\n'
+            '\n'
             'To prevent from printing the relation, append a ; to the end of the query.\n'
+            '\n'
             'To insert relational operators, type _OPNAME, they will be internally replaced with the correct symbol.\n'
+            '\n'
             'Rember: completion is enabled and can be very helpful if you can\'t remember something.'
         )
         return
@@ -301,7 +308,7 @@ def exec_query(command: str) -> None:
 
         if printrel:
             print()
-            print(result)
+            print(result.pretty_string(tty=True))
 
         ui.relations[relname] = result