Declared licenses are inconsistent

[annieysu]

Hi colorsys owners,
We noticed that the declared license for this package is: MIT
https://github.com/netbeast/colorsys/blob/master/LICENSE.txt

But in package.json, the metadata license is defined as : ISC.
https://github.com/netbeast/colorsys/blob/master/package.json#L18C3-L18C20

Would you please clarify if they should be consistent?
How could we conclude the license for this package?

Thanks!