This is what I found that I thought might be useful. I don't know a lot about colorings and I can't find anything specifically to the bundling together of multiple colorings.
Based on what I looked at it seems like it would be labeled last and stated as "Contains 2 percent of less of color 1, color 2, color 3, etc.
or
"Less than 2 percent of color 1, color 2, color 3, etc.
but you have to be sure that it is not more than 2% otherwise you can't use the quantifying phrase/statement
https://www.fda.gov/...Guide-(PDF).pdf - FDA Labelling Guide
C3. What ingredient listing is used for artificial colors?
Answer: It depends on whether the artificial color is a certified color: Certified colors: List by specific or abbreviated name such as “FD&C Red No. 40” or “Red 40.” Noncertified colors: List as “artificial color,” “artificial coloring,” or by their specific common or usual names such as “caramel coloring” and “colored with beet juice.” 21 CFR 101.22(k)(1) and (2), 21 CFR 74
C4. Do certified color additive lakes have to be declared separately from the certified color in the ingredient statement?
Answer: Yes. Certified color additives and their lakes are separate ingredients and, thus, must be declared separately in the ingredient statement. 21 CFR 101.22 (k)(1)
21 CFR 101.22
(k) The label of a food to which any coloring has been added shall declare the coloring in the statement of ingredients in the manner specified in paragraphs (k)(1) and (k)(2) of this section, except that colorings added to butter, cheese, and ice cream, if declared, may be declared in the manner specified in paragraph (k)(3) of this section, and colorings added to foods subject to §§ 105.62 and 105.65 of this chapter shall be declared in accordance with the requirements of those sections.
(1) A color additive or the lake of a color additive subject to certification under 721© of the act shall be declared by the name of the color additive listed in the applicable regulation in part 74 or part 82 of this chapter, except that it is not necessary to include the "FD&C" prefix or the term "No." in the declaration, but the term "Lake" shall be included in the declaration of the lake of the certified color additive (e.g., Blue 1 Lake). Manufacturers may parenthetically declare an appropriate alternative name of the certified color additive following its common or usual name as specified in part 74 or part 82 of this chapter.
(2) Color additives not subject to certification and not otherwise required by applicable regulations in part 73 of this chapter to be declared by their respective common or usual names may be declared as "Artificial Color," "Artificial Color Added," or "Color Added" (or by an equally informative term that makes clear that a color additive has been used in the food). Alternatively, such color additives may be declared as "Colored with ________________" or "________________ color," the blank to be filled in with the name of the color additive listed in the applicable regulation in part 73 of this chapter.
How do I know whether color additives are in my food?
The FDA requires food manufacturers to list all ingredients on the label, with the ingredients used in the greatest amount first, followed in descending order by those in smaller amounts. The label must list the names of any FDA-certified color additive (e.g., FD&C Blue No. 1 or the abbreviated name, Blue 1). With the exception of carmine/cochineal extract, color additives exempt from certification can be listed collectively as “artificial colors,” “artificial color added,” “color added,” or equally informative terms, without naming each one. Because of potential allergic reactions in some people, carmine/cochineal extract are required to be identified by name on food labels.
21 CFR 101.4
The descending order of predominance requirements of paragraph (a)(1) of this section do not apply to ingredients present in amounts of 2 percent or less by weight when a listing of these ingredients is placed at the end of the ingredient statement following an appropriate quantifying statement, e.g., “Contains __ percent or less of ______” or “Less than __ percent of ______.” The blank percentage within the quantifying statement shall be filled in with a threshold level of 2 percent, or, if desired, 1.5 percent, 1.0 percent, or 0.5 percent, as appropriate. No ingredient to which the quantifying phrase applies may be present in an amount greater than the stated threshold.