Welcome to the forum
@Wendy1905
Sorry to hear about your colostomy bag and the extra complexities it is adding to your diabetes management.
We have had a number of members over the years with a stoma, there are a number of threads here which you might find helpful
Low salt intake advice will be related to heart disease risk, and blood pressure. People with diabetes have a statistically higher risk of heart disease, and high blood pressure can also cause additional problems with fine blood vessels, alongside BPs impact on heart health.
It’s always tricky to balance the needs of multiple conditions, especially where one like diabetes has quite wide-reaching recommendations because of related risks and complications.
I think this is really something you will need to talk to your Drs about, who should be able to help you balance the varying requirements.
My (unqualified) suspicion would be that for your diabetes the primary thing to aim for will be glucose management, which will most significantly be impacted by the amount and types of carbohydrate you are eating - along with trying to keep your weight in a good place.
Good luck, and let us know how things go.