Which stage takes pretty much the same amount of time regardless of cell type? explain

The most appropriate answer would be mitosis or M phase.

Mitosis or M phase is the cell cycle phase in which nuclear contents of the parent cell is equally divided into two daughter cells.

It is subdivided into four stages:

It is then followed by cytokinesis in which the cytoplasm or cellular components are divided into two daughter cells.

As this phase does not include synthesis or growth of a cell, it takes pretty much the same time irrespective of the cell type.

not only is it colder, it also becomes darker, less salty, and more dense.