Need Help changing my default text size.

So I would like to increase the size of my paragraph in the visual editor. The people who designed my website said the change would be made in the text elements area but I have included more just in case. If anyone can help me that would be great. I would also like to change the default color on the headings to where it is the same as the default paragraph settings.

/* =Global Elements
————————————————————– */

/* Main global ‘theme’ and typographic styles */
body {
background: #1c2431;
}
body,
input,
textarea {
color: #666;
font-size: 12px;
line-height: 18px;
}
hr {
background-color: #e7e7e7;
border: 0;
clear: both;
height: 1px;
margin-bottom: 18px;
}

/* Text elements */
p {
margin-bottom: 18px;
}
ul {
list-style: square;
margin: 0 0 18px 1.5em;
}
ol {
list-style: decimal;
margin: 0 0 18px 1.5em;
}
ol ol {
list-style: upper-alpha;
}
ol ol ol {
list-style: lower-roman;
}
ol ol ol ol {
list-style: lower-alpha;
}
ul ul,
ol ol,
ul ol,
ol ul {
margin-bottom: 0;
}
dl {
margin: 0 0 24px 0;
}
dt {
font-weight: bold;
}
dd {
margin-bottom: 18px;
}
strong {
font-weight: bold;
}
cite,
em,
i {
font-style: italic;
}
big {
font-size: 131.25%;
}
ins {
background: #ffc;
text-decoration: none;
}
blockquote {
font-style: italic;
padding: 0 3em;
}
blockquote cite,
blockquote em,
blockquote i {
font-style: normal;
}
pre {
background: #f7f7f7;
color: #222;
line-height: 18px;
margin-bottom: 18px;
overflow: auto;
padding: 1.5em;
}
abbr,
acronym {
border-bottom: 1px dotted #666;
cursor: help;
}
sup,
sub {
height: 0;
line-height: 1;
position: relative;
vertical-align: baseline;
}
sup {
bottom: 1ex;
}
sub {
top: .5ex;
}
input[type=”text”],
textarea {
background: #f9f9f9;
border: 1px solid #ccc;
box-shadow: inset 1px 1px 1px rgba(0,0,0,0.1);
-moz-box-shadow: inset 1px 1px 1px rgba(0,0,0,0.1);
-webkit-box-shadow: inset 1px 1px 1px rgba(0,0,0,0.1);
padding: 2px;
}
a:link {
color: #0066cc;
}
a:visited {
color: #743399;
}
a:active,
a:hover {
color: #ff4b33;
}

/* Text meant only for screen readers */
.screen-reader-text {
position: absolute;
left: -9000px;
}

/* =Header
————————————————————– */

#header {
padding:0;
}
#site-title {
float: left;
font-size: 30px;
line-height: 36px;
margin: 0 0 18px 0;
width: 700px;
}
#site-title a {
color: #000;
font-weight: bold;
text-decoration: none;
}
#site-description {
clear: right;
float: right;
font-style: italic;
margin: 15px 0 18px 0;
width: 220px;
}

/* This is the custom header image */
#branding img {
border-top: 4px solid #000;
border-bottom: 1px solid #000;
display: block;
float: left;
}

/* =Menu
————————————————————– */

#access {
background: url(“images/top-menu-bg.png”) no-repeat scroll 0 0 rgba(0, 0, 0, 0);
display: block;
float: left;
margin: 0 auto;
padding: 12px 0;
width: 980px;
}
#access .menu-header,
div.menu {
font-size: 13px;
margin-left: 12px;
width: 928px;
}
#access .menu-header ul,
div.menu ul {
list-style: none;
margin: 0;
}

#access .menu-header li, div.menu li {
background: url(“images/top-menu-border.png”) no-repeat scroll 0 -12px rgba(0, 0, 0, 0);
float: left;
padding: 0 17.5px;
position: relative;
}
#access a {
border-radius: 5px;
color: #FFFFFF;
display: block;
font-family: ‘pt_sansregular’;
font-size: 15px;
line-height: 37px;
padding: 0 10px;
text-decoration: none;
}
#access ul ul {
box-shadow: 0px 3px 3px rgba(0,0,0,0.2);
-moz-box-shadow: 0px 3px 3px rgba(0,0,0,0.2);
-webkit-box-shadow: 0px 3px 3px rgba(0,0,0,0.2);
display: none;
position: absolute;
top: 38px;
left: 0;
float: left;
width: 180px;
z-index: 99999;
}
#access ul ul li {
min-width: 180px;
}
#access ul ul ul {
left: 100%;
top: 0;
}
#access ul ul a {
background: #333;
line-height: 1em;
padding: 10px;
width: 160px;
height: auto;
}
#access li:hover{background:none !important;}
#access li:hover > a,
#access ul ul :hover > a {
background: #4c7800;
color: #fff;
}
#access ul li:hover > ul {
display: block;
}
#access ul li.current_page_item > a,
#access ul li.current-menu-ancestor > a,
#access ul li.current-menu-item > a,
#access ul li.current-menu-parent > a {
color: #fff;
background: #4c7800;
}
* html #access ul li.current_page_item a,
* html #access ul li.current-menu-ancestor a,
* html #access ul li.current-menu-item a,
* html #access ul li.current-menu-parent a,
* html #access ul li a:hover {
color: #fff;
}