Cork County Council has said it is happy with the peach/pink shade chosen by actor Jeremy Irons to paint Kilcoe Castle, near Ballydehob.
Duchas said while it was not opposed to the colour, it should have been notified.
Mr Irons had permission to carry out renovation work on the listed 15th century castle and the council was pleased with the work so far, a council spokesman said. The colour was a mixture of lime-wash and sulphate and would oxidise, fading in colour, the spokesman added.
He said he was aware of concerns that if the castle had been painted a lighter colour, such as white, it would have "stuck out like a beacon".
"It's a traditional shade to paint . . . it will mature and settle," he said.
No complaints have been received by the council from neighbours concerned at the colour, the spokesman added.
The shade has, however, attracted local attention. "It looks as if Don Quixote is going to land in it," was one comment.
A ferry owner in Cape Clear has taken to pointing the castle out to tourists and it is felt locally that the pubs of the town may benefit from curiosity among people from Cork and surrounding areas.
Another local said people could not understand why the castle was painted such an unusual colour. "It strikes me as something that should be in Mexico."
Mr Irons, who starred in The Mission, Brideshead Revisited and Lolita, announced three years ago he would spend £1 million restoring the castle. Along with his actor wife, Sinead Cusack, Mr Irons also owns a property in Skibbereen.
Kilcoe Castle was the site of the last stand against the English by the McCarthy clan in west Cork in 1603, before the local clans were finally subdued.
Mr Irons has said he hoped to restore the castle to its original splendour, replicating as near as possible the original architecture and style.