"sail under false colors" meaning in English

{
  "forms": [
    {
      "form": "sails under false colors",
      "tags": [
        "present",
        "singular",
        "third-person"
      ]
    },
    {
      "form": "sailing under false colors",
      "tags": [
        "participle",
        "present"
      ]
    },
    {
      "form": "sailed under false colors",
      "tags": [
        "participle",
        "past"
      ]
    },
    {
      "form": "sailed under false colors",
      "tags": [
        "past"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "*"
      },
      "expansion": "sail under false colors (third-person singular simple present sails under false colors, present participle sailing under false colors, simple past and past participle sailed under false colors)",
      "name": "en-verb"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Nautical",
          "orig": "en:Nautical",
          "parents": [
            "Transport",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1869, Annie Thomas, “Miss Vargrave Nearly Lands a Fish”, in False Colours. […], volume II, London: Tinsley Brothers, […], →OCLC, page 251:",
          "text": "They were all not exactly sailing under false colours, but deceiving themselves as to their motives—and one another, to a lesser degree, by their actions.",
          "type": "quote"
        }
      ],
      "glosses": [
        "To deceive or intentionally mystify."
      ],
      "id": "en-sail_under_false_colors-en-verb-KqOlMAZG",
      "links": [
        [
          "nautical",
          "nautical"
        ],
        [
          "deceive",
          "deceive"
        ],
        [
          "intentionally",
          "intentionally"
        ],
        [
          "mystify",
          "mystify"
        ]
      ],
      "raw_glosses": [
        "(idiomatic, nautical, obsolete) To deceive or intentionally mystify."
      ],
      "tags": [
        "idiomatic",
        "obsolete"
      ],
      "topics": [
        "nautical",
        "transport"
      ]
    }
  ],
  "word": "sail under false colors"
}

{
  "forms": [
    {
      "form": "sails under false colors",
      "tags": [
        "present",
        "singular",
        "third-person"
      ]
    },
    {
      "form": "sailing under false colors",
      "tags": [
        "participle",
        "present"
      ]
    },
    {
      "form": "sailed under false colors",
      "tags": [
        "participle",
        "past"
      ]
    },
    {
      "form": "sailed under false colors",
      "tags": [
        "past"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "*"
      },
      "expansion": "sail under false colors (third-person singular simple present sails under false colors, present participle sailing under false colors, simple past and past participle sailed under false colors)",
      "name": "en-verb"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English idioms",
        "English lemmas",
        "English multiword terms",
        "English terms with obsolete senses",
        "English terms with quotations",
        "English verbs",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Nautical"
      ],
      "examples": [
        {
          "ref": "1869, Annie Thomas, “Miss Vargrave Nearly Lands a Fish”, in False Colours. […], volume II, London: Tinsley Brothers, […], →OCLC, page 251:",
          "text": "They were all not exactly sailing under false colours, but deceiving themselves as to their motives—and one another, to a lesser degree, by their actions.",
          "type": "quote"
        }
      ],
      "glosses": [
        "To deceive or intentionally mystify."
      ],
      "links": [
        [
          "nautical",
          "nautical"
        ],
        [
          "deceive",
          "deceive"
        ],
        [
          "intentionally",
          "intentionally"
        ],
        [
          "mystify",
          "mystify"
        ]
      ],
      "raw_glosses": [
        "(idiomatic, nautical, obsolete) To deceive or intentionally mystify."
      ],
      "tags": [
        "idiomatic",
        "obsolete"
      ],
      "topics": [
        "nautical",
        "transport"
      ]
    }
  ],
  "word": "sail under false colors"
}