diff --git a/sysapps/helloworld.c b/sysapps/helloworld.c
index 255f881..5f18a95 100644
--- a/sysapps/helloworld.c
+++ b/sysapps/helloworld.c
@@ -1,5 +1,13 @@
 #include "aster_api.h"
+#include "display.h"
+#include "printk.h"
 
 void init(void) {
-    aster_api_print("Hello, world!");
+    for (int col = 0x01; col <= 0x0F; col++) {
+        display_set_color(col, 0x00);
+        printk("Hello, world! (0x0%d)\n", col);
+    }
+
+    aster_api_print("\n");
+    display_set_color(0x0F, 0x00);
 }