1) Generally speaking, you should not arbitrarily alter the Grid itself. Instead you can use a custom class:
.no-gutter >[class*='col-'] {
padding-right: 0;
padding-left: 0;
}
This will allow you to adjust the column padding (and whatever other rules concerning columns) to whatever you need.
2) Or if you use SASS you can use the below Variable to adjust the padding.
//** Padding between columns. Gets divided in half for the left and right.
$grid-gutter-width: 30px !default;
3) And you can use a custom build as well if it makes sense. See Customize Grid System.
See examples in Snippet.
body,
html {
padding-top: 20px;
}
.lightblue {
background: lightblue;
}
.red {
background: #f00;
}
.box {
background: #ddd;
padding: 20px;
}
.box2 {
background: #f00;
color: white;
padding: 20px;
margin: 1px;
}
.box3 {
background: #444;
padding: 20px;
margin: 1px;
color: white;
}
.no-gutter >[class*='col-'] {
padding-right: 0;
padding-left: 0;
}
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet" />
<div class="container">
<h3>Original Grid</h3>
<div class="row lightblue">
<div class="col-md-4">
<div class="box">A</div>
</div>
<div class="col-md-4">
<div class="box">B</div>
</div>
<div class="col-md-4">
<div class="box">C
<ul>
<li>example</li>
<li>example</li>
<li>example</li>
<li>example</li>
<li>example</li>
</ul>
</div>
</div>
</div>
<div class="row lightblue">
<div class="col-md-4">
<div class="box">HEY</div>
</div>
<div class="col-md-4">
<div class="box">HEY</div>
</div>
<div class="col-md-4">
<div class="box">HEY</div>
</div>
</div>
</div>
<hr>
<div class="container">
<h3>Your example Grid</h3>
<div class="row lightblue">
<div class="col-md-4">
<div class="box2">A</div>
</div>
<div class="col-md-4">
<div class="box2">B</div>
</div>
<div class="col-md-4">
<div class="box2">C
<ul>
<li>example</li>
<li>example</li>
<li>example</li>
<li>example</li>
<li>example</li>
</ul>
</div>
</div>
</div>
<div class="row lightblue">
<div class="col-md-4">
<div class="box2">HEY</div>
</div>
<div class="col-md-4">
<div class="box2">HEY</div>
</div>
<div class="col-md-4">
<div class="box2">HEY</div>
</div>
</div>
</div>
<hr>
<div class="container">
<h3>Columns with Zero Padding | Outcome</h3>
<div class="row no-gutter red">
<div class="col-md-4">
<div class="box3">A</div>
</div>
<div class="col-md-4">
<div class="box3">B</div>
</div>
<div class="col-md-4">
<div class="box3">C
<ul>
<li>example</li>
<li>example</li>
<li>example</li>
<li>example</li>
<li>example</li>
</ul>
</div>
</div>
</div>
<div class="row no-gutter red">
<div class="col-md-4">
<div class="box3">HEY</div>
</div>
<div class="col-md-4">
<div class="box3">HEY</div>
</div>
<div class="col-md-4">
<div class="box3">HEY</div>
</div>
</div>
</div>