はてなブログテーマ「Palette(パレット)」の着せ替えコードです。
ブルーのストライプです★
爽やか&キュートなイメージにしました♪♪

テーマ「パレット」をインストール後、
↓↓こちらを「デザイン」→「カスタマイズ」→「{}デザインCSS」にコピペしてください。
/*===================
blue stripe
===================*/
/*=== header ===*/
body{background:repeating-linear-gradient(90deg, #f0f8ff, #f0f8ff 30px, #fff 0, #fff 60px);}
#title{padding-top:100px}
/*=== basic settings ===*/
#title a:hover,#blog-description,
.date a:hover,a:hover,.categories a,
.hatena-module-profile .id a,
.hatena-urllist .urllist-date-link a,
:not(.permalink)>.pager-next a,
.hatena-urllist .urllist-category-link a,
.categories a,.entry-title a,
ul.navi-top a,ul.navi-top a:hover,
.leave-comment-title,
:not(.permalink)>.pager-next a,
#globalheader-container,
#footer, #footer a,
.bottom-menu li a,
ul.menu-second-level li a,
.bottom-menu li a:hover,
h1,h2,h3,h1 a,h2 a,h3 a
{color: #1670b9;}
/*=== borders ===*/
.entry-content hr,.urllist-item,
.page-archive .archive-entry,
ul.table-of-contents:before,
.comment-box .entry-comment,
#globalheader-container,
ul.navi-top
{border-bottom: 1px solid #1670b9;}
.entry-header,
.entry-content h3,ul.bottom-menu
{border-bottom: 2px solid #1670b9;}
.entry-content h3,ul.bottom-menu
{border-top: 2px solid #1670b9;}
.comment-box .entry-comment:first-child,
ul.menu-second-level li a
{border-top: 1px solid #1670b9;}
.categories a,
.leave-comment-title,
:not(.permalink)>.pager-next a
{border: 1px solid #1670b9;}
.entry-content h2
{border-left: 7px solid #1670b9;}
#blog-title,.entry-content h1
{border-bottom:5px solid #1670b9;}
.entry-content blockquote
{border-left:35px solid #1670b9;}
.entry-content h4
{border-left: 7px solid #cce5ff;}
/*=== hover ===*/
a,#title a,.date a,
.hatena-module-profile .id a:hover,
.hatena-urllist .urllist-date-link a:hover,
.hatena-urllist .urllist-category-link a:hover,
.entry-title a:hover,.categories a:hover,
:not(.permalink)>.pager-next a:hover,
.leave-comment-title:hover,
ul.table-of-contents li a:hover,
h1 a:hover, h2 a:hover, h3 a:hover,
h4 a:hover, h5 a:hover, h6 a:hover
{color: #2b9cb8;}
ul.navi-top a:hover{
color: #cce5ff;
background-color: #2b9cb8;}
/*=== background ===*/
.date a,
.hatena-urllist .urllist-date-link a,
.hatena-urllist .urllist-category-link a,
.entry-content h1,
.entry-content h2,
.entry-content h3,
#globalheader-container,
ul.navi-top,ul.navi-top a,
ul.bottom-menu,
ul.bottom-menu li,
ul.menu-second-level li a
{background-color: #cce5ff;}
.entry-content blockquote,html,body,
ul.table-of-contents,.entry-content pre.code
{background-color: #f0f8ff;}
.entry-content pre .code:before,
ul.menu-second-level li a:hover
{background-color: #1670b9;}
/*=== navi-top ===*/
ul.navi-top li a::before
{letter-spacing: 0.5em;}
/*=== bottom-menu ===*/
ul.menu-second-level li a:hover
{color:white;}
/*=== footer ===*/
#footer{margin-top:0; border-top:2px solid #1670b9;}
#footer a{background-color:transparent;}
/*=== title font + size ===*/
body{font-family:'Calibri','Corbel','Trebuchet MS', 'Avenir','Avenir Next',YuGothic,'Yu Gothic',sans-serif;}
#title{font-size:2rem;}
/*== icons ==*/
ul.table-of-contents li:before
{font-family:"blogicon";
content:"\f006";}
.hatena-module-title:before,.hatena-module-title:after
{font-family:"blogicon";content:"\f716";color:#1670b9;padding:0 10px;}
/*=== side module ===*/
.hatena-module-title{
text-align:center;
color:#1670b9;
background: repeating-linear-gradient(90deg, #f0f8ff, #f0f8ff 20px, #fff 0, #fff 40px);
padding:5px;border-radius:5px 5px 0px 0px;border-bottom:3px solid #1670b9;}
.hatena-module-title a{
color:#1670b9;}
.hatena-module-title a:hover{
color:#2b9cb8;}