Sum of entered numeric values

The simplest solution would be to use calculation scripts on the total fields.  But if the calculation buttons are really needed, then yes, you can use a MouseUp script on each button to perform the calculation and change field colors. 

And Yes you can write one script that will work for all the calculations, and it can be exactly the same script with no changes for field names.  The trick to writing this type of script is the field naming. The fields have to be named in such a way that the script can automatically generate the names from the name of the field executing the script, i.e, the button name in this case.

You're names are not the best, but they'll do.  For example, the buttons are all named with the pattern "Calc##".  The script would extract the "##" from the end of the name and then use it to build the required fields names like this:

var strColName = event.targetName.match(/\d{2,3}$/)[0];

var oFldTotal = this.getField(strColName + "T");
oFldTotal.value = Number(this.getfield("V"+strColName).value) + Number(this.getfield("A"+strColName).value) +  ...etc.

if(oFldTotal < 10)
   oFldTotal.fillColor = color.red;
else if (oFldTotal < 20)
   oFldTotal.fillColor = color.blue;
 ...etc...

You can use script at validation of total field, just change values and colors to what you want them to be and add more 'else if' statements as needed:

if(event.value == 1)event.target.fillColor = color.green;
else if(event.value == 2)event.target.fillColor = color.yellow;