I want to set a color for my tif, but a blue area appears around it

[heian911]

[mike-000]

If nodata is autodetected there will be another band for alpha

color: [
  'case',
  ['==', ['band', 2], 0],
  [0, 0, 0, 0],
  [
    'interpolate',
    ['linear'],
    ['band', 1],

    ...

  ],
],

If your data is being reprojected and the reprojected tiles are not aligned with the source grid you may need to specify

nodata: NaN,

to force an alpha band to added. See also #15042 (comment) and #15048

[heian911]

如果自动检测到无数据，则会有另一个 alpha 波段

color: [
  'case',
  ['==', ['band', 2], 0],
  [0, 0, 0, 0],
  [
    'interpolate',
    ['linear'],
    ['band', 1],

    ...

  ],
],

如果您的数据正在重新投影并且重新投影的图块未与源网格对齐，您可能需要指定

nodata: NaN,

强制添加 alpha 带。另请参见#15042（评论）和#15048

Thanks. But I have a question, why the color is beyond the range of tif?

[mike-000]

The reprojected tiles for EPSG:3857 use the default grid for EPSG:3857. If there is no alpha in the output the overflow area will appear as the color for value zero