OMNE SOLUM FORTI PATRIA
"Every land is a homeland for the courageous man"
The key evidence that these colors were carried by Burleigh's Regt is the use of the Balfour motto, "OMNE SOLUM FORTI PATRIA" and the "maiden" device. I made a quick search on the interwebs, but I cannot find any independent verification that the Lords of Burleigh ever used this particular maiden device. However, I did find that the mermaid is a common device, and given the colors had been damaged, perhaps the image or the desrcription has been misinterpreted over the years.
A quick google search indicates that the version of the mermaid associated with Burleigh is shown above, in which the maid is shown arms up on both sides (as in the maiden device) but is holding a snake and a swan or goose head. I think it looks quite similar to the "Maiden" device described by Fisher.
The latin Balfour motto, "OMNE SOLUM FORTI PATRIA", is written in red on the gold scroll work. It translates as "Every land is a homeland for the courageous man", and is a quotation from Roman poet Ovid (43BC to 17AD); a verse from book I, line 493 of "Fasti" (Festivals).
The second motto on the colonels color is gold in color and is the standard post-1650 covenanter inscription, "COVENANT FOR RELIGION KING AND KINGDOMES". Most regimental colors captured at Dunbar bore this version of the motto, and that makes these flags anachronistic for 1644.
The other peculiarity of this set of colors is the choice of a black field. While black fields are used in company colors, the use of black on a colonels color is highly unusual, the convention at the time being a white field.
An example of a reproduction black ensign is shown below. This was provided by Martin Scott, a follower of this blog, and native of Auldearn, who is a member of the Sealed Knot and a re-enactor in Sir Arthur Erskine's Regiment of Foot, another regiment with black ensigns. Erskine's Regt was raised in 1643 and served in Leven's army at Marston Moor. The motto used pre-dates the 1650 standard.
The use of black is also unusual given the recruiting area in Fife. Most Fife regiments raised at this time adopted a yellow field with white saltire for company colors. Given these departures from the norms I have assumed (as did Reid) that Burleigh would have used a similar scheme for the regiment raised in 1644, albeit with a more archaic covenanter motto.
This is my third set of flags prepared for a covenanter regiment, the first being Campbell of Lawers' Regt (which I made for Roy's first painted unit - Roy decided to hand draw and paint the rest of his flags on foil), the second was the Earl of Sutherland's Regt.