Jim Wallace told MSPs on Tuesday that it would be expensive and difficult to enforce an exact shade of blue on the Saltire.

He rejected pressure from the Scottish Parliament's petitions committee to specify the colour of the St Andrew's Cross.

But the committee then held a further discussion on the issue - and called on Mr Wallace to reconsider the matter and define the colour blue.

King Angus led prayers for deliverance and was rewarded by seeing a cloud formation of a white Saltire... against a clear blue sky

George Reid

MSPs insisted he should at least fix a recommended colour for flag manufacturers and others so that all Scottish flags could start out the same colour.

The decision was welcomed by Scottish National Party MSP Gil Paterson, who accused ministers of abdicating their responsibility.

He said: "The executive is being ridiculous in stating that they cannot define the exact colour of the Saltire because it will fade.

"Do they think that it is only flags in Scotland which fade?

"They seem to have missed the whole point on this issue, which is not about ensuring that the flags always stay the same colour but that they start off the same colour when they are manufactured."

MSPs had argued that the issue - which was raised by Edinburgh man George Reid - was a matter of national honour.

Array of blues

At first it was thought the matter was reserved to Westminster.

However, the Lord Lyon intervened to say it was the responsibility of the parliament north of the border.

Mr Reid took his case to Holyrood after becoming fed up seeing the Saltire paraded in an array of blues.

Jim Wallace: No plans for legislation

He petitioned the new Scottish Parliament, asking it to lay down one standard colour.

"It is a matter of regret that this flag, with its proud origins, should be devalued by being made and flown with varying background shades," he said.

"No other country's flag is made with varying backgrounds.

"If you watch TV pictures of Murrayfield or Hampden Park, you will see every shade of blue, from duck egg to navy blue.

"It's something we should be quite ashamed of."

Mr Reid said the flag should be the colour of a clear, blue sky. He said he owned a Saltire but rarely flew it.

Patron saint

He urged the Scottish Executive to invite the Scottish Flag Trust to take the lead in drafting a new flag code and specify the colour.

The history of the flag is said to date back to 832AD and a battle at Athelstaneford, in East Lothian, where Pictish and Scottish warriors under Angus MacFergus and Eochaidh of Dalriada defeated a larger force of Angles and Saxons.

Mr Reid said: "Fearful of the outcome, King Angus led prayers for deliverance and was rewarded by seeing a cloud formation of a white Saltire - the diagonal cross against which Saint Andrew had been martyred - against a clear blue sky.

"The King vowed that if he gained the victory then Andrew would be the patron saint of Scotland."