if it's only about changing colors, and style, you can do it via css or js.
All the multiple numerical question html is inside a div, with the class
numeric-multi. Just use firebug to explore the code and find the the different classes/elements of your question and edit the template.css of your template.
If you want to change the DOM (the HTML itself), the best way to do it for now is to use JavaScript.
If you really really want to change the HTML flow of the multiple numerical question, without using javascript, you can't do it from the template itself. You must hack the LimeSurvey kernel code. The HTML of the multiple numerical question is generated in the file
application/helpers/qanda_helper.php in the function
do_multiplenumeric :
github.com/LimeSurvey/LimeSurvey/blob/ma...nda_helper.php#l2996
Of course, any modification you do to this file will be overwritten by further updates.