I wish to result in the first word of the widget title another color.

The widget code is:

'before_title' => '<h3 class="widget-title">',
'after_title' => '</h3>',

How do i were built with a span or perhaps a class inside in order to specify another color in css?

I believe you cannot do that just by modifying widget code. If you actually need first word outlined, you might search for some javascript, jquery solution like here: First word selector