load list of string with ':' in it, get different result with BaseLoader and SafeLoader

[beegerous]

file content:

a: 1
b:
  - 10:0
  - 100:0

my code

import yaml

print(yaml.__version__)
c = yaml.safe_load(open("./in"))
print(c)
c = yaml.unsafe_load(open("./in"))
print(c)
c = yaml.full_load(open("./in"))
print(c)
c = yaml.load(open("./in"), Loader=yaml.BaseLoader)
print(c)

and get result:

5.3
{'a': 1, 'b': [600, 6000]}
{'a': 1, 'b': [600, 6000]}
{'a': 1, 'b': [600, 6000]}
{'a': '1', 'b': ['10:0', '100:0']}

[perlpunk]

This works as expected.
The BaseLoader loads everything as a string: https://pyyaml.org/wiki/PyYAMLDocumentation
The other loaders implement the YAML 1.1 types, and the integer type includes sexagesimals (numbers with base 60), which are seperated by colons: https://yaml.org/type/int.html