Sample data I had laying around is points (table view below):
I wrote a quick model that takes the first 3 records above, writes them to another table and sums the "color" values for each row (I.E. Red, Yellow, etc).
1) First thing I did was create a blank table in my database (not a feature class) that has the format I want in my output (in my case just the starting table with a field to hold the sum of the "Color" values). This is the file I'm going to append the results of the "Select by Attributes" to and the table I'm going to "Calculate Field" against. Initially its empty.... see I just added a "ColorTotal" field to the schema of the input table, but yours can be more complex.
2) Next I wrote the sub-model. Instead of writing 6 selects I used a "MultiValue" iterator and used its %value% as input into my "Select Layer By Attribute" tool. The results of that tool I appended to the table I created in step one (TestCal in my case).
3) The last step was to create the "Main" model that uses the sub-model created in step 2. All this model does is uses the output of the sub model (the TestCalc table) as input into a "Calculate Field" tool.
The result being: