diff --git a/README.md b/README.md
index f3a4003..3a5dbba 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@ Captcha Gem for Rails, which generates captcha image by Rust.
 
 ## Example
 
-![1](https://user-images.githubusercontent.com/5518/195587367-6b579046-1d75-4a64-8e8f-4475da8932fa.png) ![2](https://user-images.githubusercontent.com/5518/195587377-08065df4-80ad-4c3f-baf4-2da7f9919b19.png) ![3](https://user-images.githubusercontent.com/5518/195587383-de8f73ea-e934-4c9d-b278-c78fb69cad58.png) ![4](https://user-images.githubusercontent.com/5518/195587381-a67e586d-0b54-4d6f-89c8-a431b085e16c.png)
+<img src="https://user-images.githubusercontent.com/5518/196329734-fee49f62-050b-44c8-a5a8-7ffdd3c5a3f6.png" height="50" alt="0"> <img src="https://user-images.githubusercontent.com/5518/196329738-64b264a1-e3fb-4804-ac46-0df18fb31d1e.png" height="50" alt="1"> <img src="https://user-images.githubusercontent.com/5518/196329740-e10ded26-ba46-4e9b-93b8-ce30c198f880.png" height="50" alt="2"> <img src="https://user-images.githubusercontent.com/5518/196329743-c7b055b8-b309-4554-8c95-66c5caf4437d.png" height="50" alt="3"> <img src="https://user-images.githubusercontent.com/5518/196329745-eb68f0c3-ccac-4fa3-aa7a-cc4c2caeb41e.png" height="50" alt="4"> <img src="https://user-images.githubusercontent.com/5518/196329746-b15a9f71-262e-4699-87c7-a5561c6caf2c.png" height="50" alt="5"> <img src="https://user-images.githubusercontent.com/5518/196329747-d111a5d3-89a1-487b-989e-5be8059488c2.png" height="50" alt="6"> <img src="https://user-images.githubusercontent.com/5518/196329749-2cb44aa3-8b59-427c-91f3-59566d6de8a5.png" height="50" alt="7"> <img src="https://user-images.githubusercontent.com/5518/196329754-ae64374b-f2e5-44b8-a7f4-3aee1405c193.png" height="50" alt="8"> <img src="https://user-images.githubusercontent.com/5518/196329755-26b88705-bf34-4d32-a4dc-076530582a90.png" height="50" alt="9">
 
 ## Feature
 
diff --git a/ext/rucaptcha/src/captcha.rs b/ext/rucaptcha/src/captcha.rs
index bb17580..7e4da34 100644
--- a/ext/rucaptcha/src/captcha.rs
+++ b/ext/rucaptcha/src/captcha.rs
@@ -14,7 +14,12 @@ static BASIC_CHAR: [char; 54] = [
 static FONT_BYTES1: &[u8; 145008] = include_bytes!("../fonts/FuzzyBubbles-Regular.ttf");
 static FONT_BYTES2: &[u8; 37792] = include_bytes!("../fonts/Handlee-Regular.ttf");
 
-static COLORS: [(u8, u8, u8); 10] = [
+// https://coolors.co/cc0b8f-7c0abe-5700c8-3c2ea4-3d56a8-3fa67e-45bb30-69d003-a0d003-d8db02
+static COLORS: [(u8, u8, u8); 14] = [
+    (197, 166, 3),
+    (187, 87, 5),
+    (176, 7, 7),
+    (186, 9, 56),
     (204, 11, 143),
     (124, 10, 190),
     (87, 0, 200),
@@ -145,7 +150,7 @@ fn draw_interference_line(num: usize, image: &mut ImageBuffer<Rgb<u8>, Vec<u8>>,
         let ctrl_x = get_next((width / 6) as f32, width / 4 * 3);
         let ctrl_y = get_next(x1, height - 5);
 
-        let ctrl_x2 = get_next((width / 4) as f32, width / 4 * 3);
+        let ctrl_x2 = get_next((width / 12) as f32, width / 12 * 3);
         let ctrl_y2 = get_next(x1, height - 5);
         // Randomly draw bezier curves
         draw_cubic_bezier_curve_mut(