Disregarding N/A in Formula

I would suggest splitting this across two separate formulas in two separate columns. One that outputs the number itself and then another to output the color.

Basically what you are going to need to do is wrap each of those portions in an IFERROR to output a zero.

=IF(SUM(IFERROR(VALUE(RIGHT([Overall Summary Cost]@row, 1)), 0), VALUE(RIGHT([Overall Summary Schedule]@row, 1)), VALUE(RIGHT([Overall Summary Risk]@row, 1))) < 5, "Blue", IF(SUM(IFERROR(VALUE(RIGHT([Overall Summary Cost]@row, 1)), 0), VAL............................................

@Ann11 My apologies. I wasn't very clear.

I actually provided two pieces.

First: "I would suggest splitting this across two separate formulas in two separate columns. One that outputs the number itself and then another to output the color."

In the first column is where you would put your SUM function that adds up each value. In the second column would be your nested IF that says if the [first column] is less than # then output "color".

The reason for splitting is simply management/personal preference as opposed to something that MUST be done. Yes. You would have an extra column and an extra formula, but both formulas combined are going to be much shorter and easier to adjust than if you were to try to combine them into a single formula.

Second: Referencing IFERROR

Each of your VALUE(RIGHT(.........)) sets should be wrapped in an IFERROR to output a zero no matter if you split it out across two columns or just update your existing formula. The root cause of the issue is that the VALUE function is throwing an error when it gets to "N/A" because "A" cannot be directly converted into a numerical value.

IFERROR(VALUE(RIGHT(.........)), 0)

@Ann11 An example of which? There is an example of the IFERROR bit just above.