The Independent (p1) reports that a joint operation involving officers from 10 councils across the region tested 70 curry dishes and found that more than half of them contained illegally high levels of artificial additives.
And they have been warned that they are putting customers at risk of allergic reactions such as rashes, boils, migraine and even asthma.
Some meals such as tandoori chicken and chicken tikka masala contained up to 16 times the recommended amounts of additives.
Fines of up to£20,000 can be imposed an repeat offenders have been warned they could face prosecution in the future.
Frank Hollywood, assistant analyst for Staffordshire CC, said: 'We are taking this seriously. Food allergies can cause a number of different reactions from rashes to boils.'
Only sauce is subject to the legislation; meat poultry and rice are exempt. Now the councils are calling for a change in the law.
Javid Choudhary, secretary of Birmingham's Asian Balti Restaurant Association, said: 'I have been in the business for 13 or 14 years and have never heard of anyone getting ill from colouring. Using natural colours does not necessarily make for a better dish. For some dishes [artificial colouring] is needed, otherwise it would look bland.'