diff --git a/src/core/debug.c b/src/core/debug.c
index ad9f0418..f433869b 100644
--- a/src/core/debug.c
+++ b/src/core/debug.c
@@ -100,6 +100,9 @@ void janet_stacktrace(JanetFiber *fiber, Janet err) {
     JanetFiber **fibers = NULL;
     int wrote_error = 0;
 
+    int print_color = janet_truthy(janet_dyn("err-color"));
+    if (print_color) fprintf(out, "\x1b[31m");
+
     while (fiber) {
         janet_v_push(fibers, fiber);
         fiber = fiber->child;
@@ -157,6 +160,8 @@ void janet_stacktrace(JanetFiber *fiber, Janet err) {
         }
     }
 
+    if (print_color) fprintf(out, "\x1b[0m");
+
     janet_v_free(fibers);
 }
 
diff --git a/src/core/vm.c b/src/core/vm.c
index 4b9de1d1..21bec2e8 100644
--- a/src/core/vm.c
+++ b/src/core/vm.c
@@ -179,7 +179,7 @@ static void vm_do_trace(JanetFunction *func) {
 static Janet call_nonfn(JanetFiber *fiber, Janet callee) {
     int32_t argn = fiber->stacktop - fiber->stackstart;
     Janet ds, key;
-    if (argn != 1) janet_panicf("%v called with arity %d, expected 1", callee, argn);
+    if (argn != 1) janet_panicf("%v called with %d arguments, possibly expected 1", callee, argn);
     if (janet_checktypes(callee, JANET_TFLAG_INDEXED | JANET_TFLAG_DICTIONARY |
                          JANET_TFLAG_STRING | JANET_TFLAG_BUFFER | JANET_TFLAG_ABSTRACT)) {
         ds = callee;
@@ -195,7 +195,7 @@ static Janet call_nonfn(JanetFiber *fiber, Janet callee) {
 /* Get a callable from a keyword method name and check ensure that it is valid. */
 static Janet resolve_method(Janet name, JanetFiber *fiber) {
     int32_t argc = fiber->stacktop - fiber->stackstart;
-    if (argc < 1) janet_panicf("method call takes at least 1 argument, got %d", argc);
+    if (argc < 1) janet_panicf("method call (%v) takes at least 1 argument, got 0", name);
     Janet callee = janet_get(fiber->data[fiber->stackstart], name);
     if (janet_checktype(callee, JANET_NIL))
         janet_panicf("unknown method %v invoked on %v", name, fiber->data[fiber->stackstart]);
diff --git a/src/mainclient/init.janet b/src/mainclient/init.janet
index 72daac4e..c6b6fbaf 100644
--- a/src/mainclient/init.janet
+++ b/src/mainclient/init.janet
@@ -92,4 +92,5 @@
       (getter (prompter p) buf))
     (def onsig (if *quiet* (fn [x &] x) nil))
     (setdyn :pretty-format (if *colorize* "%.20P" "%.20p"))
+    (setdyn :err-color (if *colorize* true))
     (repl getchunk onsig)))