Provided is a metal coloring solution for chemical conversion treatment and a method for coloring a metal, which can color a metal surface into a yellowish to brownish color tone with good treatment efficiency. The metal coloring solution for chemical conversion treatment contains: permanganic acid or a salt thereof; one or both of an inorganic acid and a salt thereof; and a condensed phosphate.

A surface-treated steel sheet includes a chemical conversion coating with a thickness of 3.0 μm or less, the chemical conversion coating being placed on a surface of a hot-dip Zn—Al alloy coated steel sheet including a hot-dip Zn—Al alloy coating film containing Al: more than 1.0 mass % and 15 mass % or less, a balance being Zn and inevitable impurities. The chemical conversion coating contains AlH.sub.2P.sub.3O.sub.10.2H.sub.2O and a compound containing one or more elements selected from Mg, Ca, and Sr such that a sum of contents of AlH.sub.2P.sub.3O.sub.10.2H.sub.2O and the compound is 3.0 mass % to 50 mass %.

A surface-treated steel sheet includes a chemical conversion coating with a thickness of 3.0 μm or less, the chemical conversion coating being placed on a surface of a hot-dip Zn—Al alloy coated steel sheet including a hot-dip Zn—Al alloy coating film containing Al: more than 1.0 mass % and 15 mass % or less, a balance being Zn and inevitable impurities. The chemical conversion coating contains AlH.sub.2P.sub.3O.sub.10.2H.sub.2O and a compound containing one or more elements selected from Mg, Ca, and Sr such that a sum of contents of AlH.sub.2P.sub.3O.sub.10.2H.sub.2O and the compound is 3.0 mass % to 50 mass %.

A surface-treated steel sheet includes a chemical conversion coating with a thickness of 3.0 μm or less, the chemical conversion coating being placed on a surface of a hot-dip Zn—Al alloy coated steel sheet including a hot-dip Zn—Al alloy coating film containing Al: more than 1.0 mass % and 15 mass % or less, a balance being Zn and inevitable impurities. The chemical conversion coating contains AlH.sub.2P.sub.3O.sub.10.2H.sub.2O and a compound containing one or more elements selected from Mg, Ca, and Sr such that a sum of contents of AlH.sub.2P.sub.3O.sub.10.2H.sub.2O and the compound is 3.0 mass % to 50 mass %.

A surface-treated steel sheet includes a chemical conversion coating with a thickness of 3.0 μm or less, the chemical conversion coating being placed on a surface of a hot-dip Zn—Al alloy coated steel sheet including a hot-dip Zn—Al alloy coating film containing Al: more than 1.0 mass % and 15 mass % or less, a balance being Zn and inevitable impurities. The chemical conversion coating contains AlH.sub.2P.sub.3O.sub.10.2H.sub.2O and a compound containing one or more elements selected from Mg, Ca, and Sr such that a sum of contents of AlH.sub.2P.sub.3O.sub.10.2H.sub.2O and the compound is 3.0 mass % to 50 mass %.

A grain-oriented electrical steel sheet according to one embodiment of the present invention includes a steel sheet and an insulation coating, in which the insulation coating contains a first metal phosphate, which is a metal phosphate of one or two more metals selected from Al, Fe, Mg, Mn, Ni, and Zn; a second metal phosphate, which is a metal phosphate of one or two more metals selected from Co, Mo, V, W, and Zr; and colloidal silica, the insulation coating does not contain chromate, and an elution amount of phosphoric acid of the insulation coating as determined by boiling the grain-oriented electrical steel sheet in a boiled pure water for 10 minutes, then measuring an elution amount of phosphoric acid into the pure water, and dividing the amount of phosphoric acid by the area of the insulation coating of the boiled grain-oriented electrical steel sheet is 30 mg/m.sup.2 or less.

A grain-oriented electrical steel sheet according to one embodiment of the present invention includes a steel sheet and an insulation coating, in which the insulation coating contains a first metal phosphate, which is a metal phosphate of one or two more metals selected from Al, Fe, Mg, Mn, Ni, and Zn; a second metal phosphate, which is a metal phosphate of one or two more metals selected from Co, Mo, V, W, and Zr; and colloidal silica, the insulation coating does not contain chromate, and an elution amount of phosphoric acid of the insulation coating as determined by boiling the grain-oriented electrical steel sheet in a boiled pure water for 10 minutes, then measuring an elution amount of phosphoric acid into the pure water, and dividing the amount of phosphoric acid by the area of the insulation coating of the boiled grain-oriented electrical steel sheet is 30 mg/m.sup.2 or less.

An aqueous anti-rust surface treatment composition used for forming a film on a surface of a metal member of the present invention contains a silane coupling agent; a water-soluble transition metal compound containing a water-soluble titanium compound or a water-soluble zirconium compound; a condensed phosphate; and a solvent containing water, in which the condensed phosphate contains a highly condensed phosphate which is a salt of high condensate of equal to or more than four phosphoric acids.

An aqueous anti-rust surface treatment composition used for forming a film on a surface of a metal member of the present invention contains a silane coupling agent; a water-soluble transition metal compound containing a water-soluble titanium compound or a water-soluble zirconium compound; a condensed phosphate; and a solvent containing water, in which the condensed phosphate contains a highly condensed phosphate which is a salt of high condensate of equal to or more than four phosphoric acids.

A grain-oriented electrical steel sheet according to one embodiment of the present invention includes a steel sheet and an insulation coating, in which the insulation coating contains a first metal phosphate, which is a metal phosphate of one or two more metals selected from Al, Fe, Mg, Mn, Ni, and Zn; a second metal phosphate, which is a metal phosphate of one or two more metals selected from Co, Mo, V, W, and Zr; and colloidal silica, the insulation coating does not contain chromate, and an elution amount of phosphoric acid of the insulation coating as determined by boiling the grain-oriented electrical steel sheet in a boiled pure water for 10 minutes, then measuring an elution amount of phosphoric acid into the pure water, and dividing the amount of phosphoric acid by the area of the insulation coating of the boiled grain-oriented electrical steel sheet is 30 mg/m.sup.2 or less.