Hair color-altering compositions

1. A hair color-altering composition comprising:

(a) about 0.05 to about 10 wt. % of at least one 3-aminopyrazolo[1,5-a]pyridine;

(b) from about 0.01 to about 1 wt. % of a reducing agent other than thiolactic acid that is a monovalent thiolactate salt;

(c) from about 0.01 to about 5 wt. % of an ammonia compound;

(d) from about 5 to about 10 wt. % of an alkanolamine;

(e) from about 0.01 to about 6 wt. % of a carboxylic acid-containing surfactant; and

(f) from about 0.01 to about 1 wt. % of an antioxidant.

2. The hair color-altering composition of claim 1 , wherein the hair color-altering composition is in the form of a microemulsion.

3. The hair color-altering composition of claim 1 , wherein the at least one 3-aminopyrazolo[1,5-a]pyridine is present in an amount of about 0.4 to about 2.5 wt. %.

4. The hair color-altering composition of claim 1 , wherein the at least one 3-aminopyrazolo[1,5-a]pyridine comprises 2-[(3-aminopyrazolo[1,5-a]pyridin-2-yl)oxy]ethanol hydrochloride.

5. The hair color-altering composition of claim 1 , wherein the at least one 3-aminopyrazolo[1,5-a]pyridine comprises 4-(3-Amino-pyrazolo[1,5-a]pyridin-2-yl)-1,1-dimethyl-piperazin-1-ium or a salt thereof.

6. The hair color-altering composition of claim 1 , wherein the monovalent thiolactate salt comprises ammonium thiolactate.

7. The hair color-altering composition of claim 1 , wherein the ammonia compound comprises ammonium hydroxide.

8. The hair color-altering composition of claim 1 , wherein the alkanolamine is present in an amount of from about 5 to about 8 wt. %.

9. The hair color-altering composition of claim 1 , wherein the alkanolamine comprises monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, N-dimethylaminoethanolamine, 2-amino-2-methyl-1-propanol, triisopropanolamine, 2-amino-2-methyl-1,3-propanediol, 3-amino-1,2-propanediol, 3-dimethylamino-1,2-propanediol, 2-amino-2-methyl-1-propanol, and tris(hydroxymethylamino)methane, and combinations thereof.

10. The hair color-altering composition of claim 9 , wherein the alkanolamine comprises monoethanolamine.

11. The hair color-altering composition of claim 1 , wherein the antioxidant comprises ascorbic acid, sodium sulfite, sodium metabisulfite, sodium hydrosulfite, tocopherols, alpha-tocopherol, tocopheryl acetate, panthenol, selenium sulfide, zinc formosulfoxylate, isoascorbic acid, magnesium ascorbyl phosphate, ascorbyl glucoside, cysteine, thiourea, glyceryl monothioglycolate, thioglycerol, 2,5-dihydroxybenzoic acid, erythorbic acid and combinations thereof.

12. The hair color-altering composition of claim 1 , wherein the carboxylic acid-containing surfactant comprises laureth-11 carboxylic acid, laureth-5 carboxylic acid, and combinations thereof.

13. The hair color-altering composition of claim 1 , wherein the composition is essentially free of a polyquaternium polymer.

14. The hair color-altering composition of claim 13 , wherein the composition is essentially free of polyquaternium-6.

15. The hair color-altering composition of claim 1 , wherein the composition is stable for at least one month.

16. The hair color-altering composition of claim 1 , wherein the composition is essentially free of thiolactic acid.

17. A hair color-altering composition comprising:

(a) about 0.05 to about 10 wt. % of 2-[(3-aminopyrazolo[1,5-a]pyridin-2-yl)oxy]ethanol hydrochloride;

(b) from about 0.01 to about 1 wt. % of ammonium thiolactate;

(c) from about 0.01 to about 5 wt. % of ammonia;

(d) from about 5 to about 10 wt. % of an monoethanolamine;

(e) from about 0.01 to about 6 wt. % of laureth-5 carboxylic acid; and

(f) from about 0.01 to about 1 wt. % of erythorbic acid.

18. A kit comprising the hair color-altering composition of claim 1 and a developer composition comprising one or more oxidizing agents.

19. A method of coloring hair, the method comprising applying the hair color-altering composition of claim 1 to hair.