Converting BLUE Inked Fountain Pens into Seven Plus Colours from Queen Food Dyes

The food dyes make good general purpose fountain pen inks.
They are FOOD DYES - made for colouring food - like icing on donuts etc...
They are NOT exterior house paint, with a guarantee 25 year life in the tropical sun.
In the general sense, they are neither archival or incredibly durable inks.
Like the old Iron Gall or Carbon Black and Honey etc., based inks that are still in closed books from 1277...
The FOOD dyes were never designed to last in strong sunlight for any length of time..
They are however, good general purpose inks for school exercise books, notes, records, shopping lists, and other short to medium term recordings, in the dark and closed books and journals.
I'd also consider the two antifungal agents that are usually added to them for concocting blends with longer storage times - in the supply and in infrequently used pens.