how to change the sidebar color of a theme?

You can do this in your CSS file. Find the name of the sidebar div and set a background color. There’s instructions on how to use the Background property here:

https://www.w3schools.com/css/css_background.asp

If you can’t make heads or tails of that, post your url so we can help you know exactly what to do.

Cheers,
Eric

this is the code

the side bar is black background with white font color

i want to edit the black background and change it to pink

how do i do that?

*/
body {margin:0 auto; width:787px; text-align:center; padding:0; font-family:arial, sans-serif; font-size:95%;position:relative; background:#fff url(bg.gif) repeat-x; color:#777;}
a {color:#777;text-decoration:none;}
h1 {font-size:175%;} h2 {font-size:150%;} h3 {font-size:125%;} h4 {font-size:105%;} h5 {font-size:75%;} h6 {font-size:50%;}
.wrapper {margin:10px auto; text-align:left; width:787px; wid\th:777px; background:#fff; position:relative; -moz-border-radius: 12px; -webkit-border-radius: 12px; padding:10px;border:1px solid #ccc;}
.header {background:url(header.gif) no-repeat;color:#fff; text-align:center; height: 108px; display:table-cell; vertical-align: middle; width:787px;}
.siteTitle a {padding-top:20px;font-size:1.75em; color:yellow; font-weight:bold;}
*:first-child+html .siteTitle a {display:block;padding-top:30px;}
*:first-child+html .menu.top {margin-top:-7px;}
.header ul, .footer ul {margin:0; padding:10px 0 0 0;}
.header ul li, .footer ul li {display:inline; padding:10px 5px 0 0;}
.header li a, .footer li a {color:#fff;font-size:.8em; padding:0 10px 0 0; border-right:1px; border-right-style:solid;}
.header ul li.last a, .footer ul li.last a {border:none;}
.footer li a {color:#777;}
.footer li.first {margin-right:5px;}
.main {background: url(sidebar.gif) right repeat-y;}
.content {float:left;width:540px; padding:15px; margin-bottom:-35px; font-size:90%;}
.sidebar {float:right; width:180px; background: url(sb-top.png) no-repeat top center; padding:20px 10px 0 10px; color:#fff; font-family:verdana; font-size:.85em;}
.sidebar ul {margin:5px 0 0 20px; padding:0;}
.sidebar ul li a {color:#fff;display:block;padding:0 0 10px 0;}
.footer {text-align:center; background:url(footer.gif) no-repeat;height:56px;color:#777}
.footer ul li.last.sitemap a {border-left:1px; border-left-style:solid;padding-left:10px;margin-left:-10px;}
.footer .copyright {padding-top:5px;font-size:.8em;}
.images img {padding:0 13px 0 0;}
.images img.last {padding-right:0;}
.menu.side h4 {margin:10px 0 5px 5px;}
#respond textarea {width:540px;}
.nocomments{background:#EDEFF0 url(messagebox.gif) no-repeat;padding:0 12px;height:27px;line-height:27px;width:510px;}
.clear {clear:both;background: url(sb-bottom.png) no-repeat right;height:18px;}
.adsense250.left {float:left;}
.content .tags, .content .post-edit-link {float:left; display:block; line-height:25px;padding:5px 20px; background:url(../../icons.gif) no-repeat 0 -490px; font-size:.85em;}
.content .post-edit-link {background-position:0 -55px;}
#respond {display:block; clear:both; font-size:.9em; padding-top:1px;}

Try editing this bit:

.sidebar {float:right; width:180px; background: url(sb-top.png) no-repeat top center; padding:20px 10px 0 10px; color:#fff; font-family:verdana; font-size:.85em;}

Change background: url(sb-top.png) no-repeat top center; to background:#fec0cb url(sb-top.png) no-repeat top center;

thanks man

appreciated