Just trying to put the text and arrow in white:
Here's the code:
<div class="input-field col s12 white-text">
<select class="white-text" id="selectSide">
<option value="All" selected>All</option>
<option value="Buy">Buy</option>
<option value="Sell">Sell</option>
</select>
<label class="white-text">Side</label>
</div>
The actual styles applied to the input, dropdown and icon are as follows:
For the icon:
.select-wrapper .caret {
fill: firebrick;
}
For the dropdown content:
.dropdown-content li span {
color: firebrick;
}
For the selected item colour:
.dropdown-content li span {
color: firebrick;
}
Obviously change firebrick to your desired colour. Side note, Materializecss hides the original select element and creates a new one with a built in dropdown - so the styles above (.dropdown-content and .select-wrapper) are dynamically generated and thus a little hard to style if you're looking at the original markup.
Working demo here.