It looks like you need to put some css into the widget itself to style it as it uses inline styles
so put something like this into the digit style field:
background: transparent; color: #900;font-family: Arial, monospace; font-weight: 900;
Unfortunately the way the CSS is added in the plugin isn’t very good for customizing so overriding the odometer-style shading is not as simple as I expected and required an edit to js/odometer.js
change
var style = {
digits: "position:absolute; height:"+this.digitHeight+"px; width:"+(this.digitWidth-(2*this.digitPadding))+"px; "+
"padding:"+this.digitPadding+"px; font-size:"+(this.digitHeight-(2*this.digitPadding))+"px; "+
"line-height:"+this.digitHeight+"px; "+
"background:black; color:white; text-align:center; "+this.fontStyle,
columns: "position:relative; float:left; overflow:hidden;"+
"height:"+this.digitHeight+"px; width:"+this.digitWidth+"px;",
highlight: "position:absolute; background:white; opacity:0.25; filter:alpha(opacity=25); width:100%; left:0px;",
lowlight: "position:absolute; background:black; opacity:0.25; filter:alpha(opacity=25); width:100%; left:0px;",
sidehighlight: "position:absolute; background:white; opacity:0.50; filter:alpha(opacity=50); height:100%; top:0px;",
sidelowlight: "position:absolute; background:black; opacity:0.50; filter:alpha(opacity=50); height:100%; top:0px;"
};
to
var style = {
digits: "position:absolute; height:"+this.digitHeight+"px; width:"+(this.digitWidth-(2*this.digitPadding))+"px; "+
"padding:"+this.digitPadding+"px; font-size:"+(this.digitHeight-(2*this.digitPadding))+"px; "+
"line-height:"+this.digitHeight+"px; "+
"background:black; color:white; text-align:center; "+this.fontStyle,
columns: "position:relative; float:left; overflow:hidden;"+
"height:"+this.digitHeight+"px; width:"+this.digitWidth+"px;"
};
The numbers are still scrolling, but the appearance is changed. I think that’s probably as close as you can get with this plugin.
An alternative would be to make or commission a new plugin, perhaps based on this script or a similar one if the license allows it: https://jsfiddle.net/YWn9t/