Marine fatigue uniforms of that era could also include a tall green forage cap that resembled a cloth shako. These had a very wide white sides and a green band. Images of these caps are rare. Originally caps are very rare. Let me see if I can find an image.
Easier to find than I thought. This a a photo from a one hour lecture I attended about Marine uniforms of the 1830s.
Perhaps for an officer?
The enlisted men's forage cap by and during the 1830s was black leather.
Going back to 1811, a black leather forage cap was first suggested:
By 1818, "common leather fatigue caps" were worn. Here's notice of a chap promoting a return to a fatigue hat, which was not ultimately approved...
From 1827, Marines at Philadelphia drilling in their gray fatigue dress:
Here's a sketch by a Navy officer of the Marines in the battle of Quallah Battoo in 1832, in their forage caps...
When the uniform was changed to green coats in 1833 (to be instituted the next year), the regulations continued the use of the same forage cap, which in 1831 was described as "black leather."
"Fatigue Cap: Same pattern as at present worn by the men."
From a description of deserters in 1839:
"They left in their fatigue dress; grey round jacket, grey pantaloons, and flat topped leather caps." [Sun, (Baltimore), 4-22-1839.]
Shortly thereafter the fatigue cap was officially changed to one of blue cloth with the May, 1839 regulations, restoring the blue uniform:
the 1839 uniform was adopted at the behest of Commandant Henderson, who complained of the green cloth, etc.
"April 22, 1839
On the 10th of April 1833 the Uniform of the Corps was changed by an order from the Dept. from blue and scarlet to green and buff.
After a trial of six years it has been found that green cloth cannot be procured to retain its color. In corroboration of this I enclose a letter from the Quartermaster and a communication from the officers on the Philadelphia Station on the subject.
Blue and scarlet have been found the most standing colors and I beg leave to recommend that the enclosed order be issued for the Uniform of the Corps to go into effect when the present supply of clothing is exhausted.
The Quartermaster will hand you this and give any explanations that may be found necessary.
Archibald Henderson, Col. Commandant."