As an addition to the solution:
ul li:before {
content: '?';
}
You can use any SVG icon as the content, such as the Font Aswesome.
ul {_x000D_
list-style: none;_x000D_
padding-left: 0;_x000D_
}_x000D_
li {_x000D_
position: relative;_x000D_
padding-left: 1.5em; /* space to preserve indentation on wrap */_x000D_
}_x000D_
li:before {_x000D_
content: ''; /* placeholder for the SVG */_x000D_
position: absolute;_x000D_
left: 0; /* place the SVG at the start of the padding */_x000D_
width: 1em;_x000D_
height: 1em;_x000D_
background: url("data:image/svg+xml;utf8,<?xml version='1.0' encoding='utf-8'?><svg width='18' height='18' viewBox='0 0 1792 1792' xmlns='http://www.w3.org/2000/svg'><path d='M1671 566q0 40-28 68l-724 724-136 136q-28 28-68 28t-68-28l-136-136-362-362q-28-28-28-68t28-68l136-136q28-28 68-28t68 28l294 295 656-657q28-28 68-28t68 28l136 136q28 28 28 68z'/></svg>") no-repeat;_x000D_
}
_x000D_
<ul>_x000D_
<li>this is my text</li>_x000D_
<li>this is my text</li>_x000D_
<li>This is my text, it's pretty long so it needs to wrap. Note that wrapping preserves the indentation that bullets had!</li>_x000D_
<li>this is my text</li>_x000D_
<li>this is my text</li>_x000D_
</ul>
_x000D_
Note: To solve the wrapping problem that other answers had:
<li>
position: absolute; left: 0
)Here are more Font Awesome black icons.
Check this CODEPEN to see how you can add colors and change their size.