Loop that skips existing iterations

Hi Knime Forum,

I have built a workflow that runs through two tables in a Data Base, then returns the unique values of the tables in the first loop as shown below:

The first loop returns the following:

| ID | Colour |
| 1  | Red    |
| 2  | Orange |
| 3  | Yellow |
| 4  | Green  |

The workflow then performs two more loops to return a table containing all the unique combinations of the values present in the first table. So the last loop node returns the following:

| Combination ID | Color  | Color  |
| 1              | Red    | Orange |
| 2              | Red    | Yellow |
| 3              | Red    | Green  |
| 4              | Orange | Red    |
| 5              | Orange | Yellow |
| 6              | Orange | Green  |
| 7              | Yellow | Red    |
| 8              | Yellow | Orange |
| 9              | Yellow | Green  |
| 10             | Green  | Red    |
| 11             | Green  | Orange |
| 12             | Green  | Yellow |

New values will be added to the Database and performing this execution will eventually become very time-consuming, therefore I want to know if there will be a way to skip existing combinations and only add the latest combinations. For example, if a 5th value is added to the first table as shown below:

| ID | Colour |
| 1  | Red    |
| 2  | Orange |
| 3  | Yellow |
| 4  | Green  |
| 5  | Blue   |

How can I constrain the workflow to only add the new combinations including the new value (Blue) without regenerating the original 12 combinations?

Any assistance will be greatly appreciated.