Here it is again --
SECTION 42. Be it further enacted, &c., That Volunteer Companies, Battalions, Regiments and Brigades may be organized in this State under the same rules as Companies, Battalions, Regiments and Brigades of the regular Militia, with the following exceptions and regulations: Each company shall consist of not less than sixty privates for Artillery and Infantry, and thirty-two for Cavalry; provided, that no Company shall have more than one hundred privates; ten companies shall form one regiment; and not less than four nor more than six Regiments shall form a Brigade, and any Company of Artillery or Cavalry may be attached to a Volunteer Brigade with the consent of the Commander-in-Chief. The volunteer companies, Regiments and Brigades may determine the mode of electing or appointing their own officers, which officers shall be the same as are provided by this act for the militia, and be subject of the Commander-in-Chief and the Major-General of the State; Provided, that any Volunteer Company, Regiment or Battalion organized according to this act, which shall not have attached itself to any Brigade within thirty days after the passage of this act may be attached by the Commander-in-Chief to any Brigade, either volunteer or militia.
In the first sentence, "may be" is a grant of permission to organize volunteers. The immediate question 'In what manner?' is answered immediately by the prepositional phrase "under the same rules". Next question 'With what differences?' is answered before the colon "with the following exceptions and regulations." Logic demands that organization of volunteers would be governed by identical rules as regular militia, the only variation allowed being explicitly stated in sentences which follow in section 42.
If you are voiding this legal construction, then Louisiana had no rules for volunteer militia. A volunteer militiaman could be anyone - man, woman, child; slave or free; any age or nationality. If reasonable people in Louisiana understood the law in this way, the newspapers would be filled with reports about companies, battalions, regiments and brigades composed of women, children, slaves, and yes - free men of color.
If Louisiana really had no rules for volunteer militia (and I disagree about that), the law which went into effect on Feb 15th left the door wide for free men of color. Heck, dogs and cats could volunteer. If so, aside from the previously existing Louisiana Native Guards, one would reasonably expect reports of new volunteer units organizing composed of free men of color. Do you know of any?