The thumb color</li>
<li><code>thumbBorderColor</code>: The thumb border color</li>
<li><code>thumbBorderWidth</code>: The width of the thumb border</li>
<li><code>curvaceousness</code> : From 0.0 for square thumbs to 1.0 for circle thumbs</li>
<li><code>lowerDisplayStringFormat</code> : display format for lower thumb value. Default to <code>%.0f</code> to display value as Int. Change this if you need to display decimal places or want a different label.</li>
<li><code>upperDisplayStringFormat</code> : displ