в css меняешь где то тут

/* Post Form */
.commFl {width:100%;padding:2px 3px;font-size:7pt;color:#989898;background:#181818;border:1px solid #292929;}
input[type='text'],input[type='password'], select {padding:2px 3px;font-size:7pt;color:#4682B4;background:url("/imgs/forumtitle.png")#181818;border:1px solid #292929;}
input[type='submit']{padding:2px 3px;font-size:7pt;color:#4682B4;background:url("/imgs/forumtitle.png")#181818;border:1px solid #292929;}
.checkbtn, .pollreSultsBut , .allUsersBtn ,.codeButtons {padding:2px 3px;font-size:7pt;color:#4682B4;background:url("/imgs/forumtitle.png")#181818;border:1px solid #292929;}
.postNameFl,.postDescrFl {background:#CACED2;border:1px solid #FFFFFF;width:500px;}
.postPollFl,.postQuestionFl {background:#292929;border:1px solid #292929;width:400px;color:#989898;}
.postResultFl {background:#CACED2;border:1px solid #FFFFFF;width:50px}
.postAnswerFl {background:#CACED2;border:1px solid #FFFFFF;width:300px}
.postTextFl {background:#292929;border:1px solid #292929;width:550px;height:150px;color:#989898}
.postUserFl {background:#CACED2;border:1px solid #FFFFFF;width:300px}
.postTextFl {width:400px;height:150px;background: url(https://diz-cs.ru/images_new/wintpost.png) no-repeat top right;border:1px solid #252525;}

.postPreview, .postReset{padding:2px 3px;font-size:7pt;color:#4682B4;background:url("/imgs/forumtitle.png")#181818;border:1px solid #292929;}
.pollHelp {font-weight:normal;font-size:7pt;padding-top:3px;}
.smilesPart {padding-top:5px;text-align:center}
/* --------- */