diff --git a/index.html b/index.html
index a0e2a86..84bf913 100644
--- a/index.html
+++ b/index.html
@@ -92,13 +92,13 @@
         <div class="container py-5">
             <div class="row align-items-center py-4">
                 <div class="col-md-6 text-center text-md-left">
-                    <h1 name="appsdownload" class="mb-4 mb-md-0 text-white">APPs DOWNLOAD</h1>
+                    <h1 name="appsdownload" class="mb-4 mb-md-0 text-primary">APPs DOWNLOAD</h1>
                 </div>
                 <div class="col-md-6 text-center text-md-right">
                     <div class="d-inline-flex align-items-center">
-                        <a name="home" class="btn text-white" href="index.html">Home</a>
-                        <i class="fas fa-angle-right text-white"></i>
-                        <a name="download" class="btn text-white disabled" href="">download</a>
+                        <a name="home" class="btn text-primary" href="index.html">Home</a>
+                        <i class="fas fa-angle-right text-primary"></i>
+                        <a name="download" class="btn text-primary disabled" href="">download</a>
                     </div>
                 </div>
             </div>
diff --git a/qa.html b/qa.html
index 0097433..66e6ddd 100644
--- a/qa.html
+++ b/qa.html
@@ -91,13 +91,13 @@
         <div class="container py-5">
             <div class="row align-items-center py-4">
                 <div class="col-md-6 text-center text-md-left">
-                    <h1 name="qa" class="mb-4 mb-md-0 text-white">Quesstion and Answer</h1>
+                    <h1 name="qa" class="mb-4 mb-md-0 text-primary">Quesstion and Answer</h1>
                 </div>
                 <div class="col-md-6 text-center text-md-right">
                     <div class="d-inline-flex align-items-center">
-                        <a name="home" class="btn text-white" href="index.html">Home</a>
-                        <i class="fas fa-angle-right text-white"></i>
-                        <a name="qa" class="btn text-white disabled" href="">Quesstion and Answer</a>
+                        <a name="home" class="btn text-primary" href="index.html">Home</a>
+                        <i class="fas fa-angle-right text-primary"></i>
+                        <a name="qa" class="btn text-primary disabled" href="">Quesstion and Answer</a>
                     </div>
                 </div>
             </div>
diff --git a/tutorial.html b/tutorial.html
index 235d931..512763a 100644
--- a/tutorial.html
+++ b/tutorial.html
@@ -70,13 +70,13 @@
         <div class="container py-5">
             <div class="row align-items-center py-4">
                 <div class="col-md-6 text-center text-md-left">
-                    <h1 name="tutorial" class="mb-4 mb-md-0 text-white">Quesstion and Answer</h1>
+                    <h1 name="tutorial" class="mb-4 mb-md-0 text-primary">Tutorial</h1>
                 </div>
                 <div class="col-md-6 text-center text-md-right">
                     <div class="d-inline-flex align-items-center">
-                        <a name="home" class="btn text-white" href="index.html">Home</a>
-                        <i class="fas fa-angle-right text-white"></i>
-                        <a name="tutorial" class="btn text-white disabled" href="">Quesstion and Answer</a>
+                        <a name="home" class="btn text-primary" href="index.html">Home</a>
+                        <i class="fas fa-angle-right text-primary"></i>
+                        <a name="tutorial" class="btn text-primary disabled" href="">Tutorial</a>
                     </div>
                 </div>
             </div>
diff --git a/user_agreement.html b/user_agreement.html
index 199e4bc..259423f 100644
--- a/user_agreement.html
+++ b/user_agreement.html
@@ -91,13 +91,13 @@
         <div class="container py-5">
             <div class="row align-items-center py-4">
                 <div class="col-md-6 text-center text-md-left">
-                    <h1 name="useragreement" class="mb-4 mb-md-0 text-white">User Agreement</h1>
+                    <h1 name="useragreement" class="mb-4 mb-md-0 text-primary">User Agreement</h1>
                 </div>
                 <div class="col-md-6 text-center text-md-right">
                     <div class="d-inline-flex align-items-center">
-                        <a name="home" class="btn text-white" href="index.html">Home</a>
-                        <i class="fas fa-angle-right text-white"></i>
-                        <a name="useragreement" class="btn text-white disabled" href="">User Agreement</a>
+                        <a name="home" class="btn text-primary" href="index.html">Home</a>
+                        <i class="fas fa-angle-right text-primary"></i>
+                        <a name="useragreement" class="btn text-primary disabled" href="">User Agreement</a>
                     </div>
                 </div>
             </div>