When the set_keepInScreenBounds method is called and you pass a true parameter, the popup of RadColorPicker is only partially visible (the tabs are hidden).
The following solution can be used:
<script>
Telerik.Web.UI.ColorPicker.LightweightRenderer.prototype.getPaletteHeight = function ($palette) {
var paletteHeight = $palette.height() +
$palette.find(".rcpTabs").height();
return paletteHeight;
}
</script>