Colons separating key and value pairs enhance readability in my book, so KDL goes too far for me. Other options are JSON5 (https://json5.org/) and CUE (https://cuelang.org/docs/introduction/). The latter is maximalist rather than minimalist, but very well thought out and worth checking out.
Really it's quite logical that the next iteration of these configuration languages be this style, remove superfluous and annoying quotes, handle comments and maybe allow trailing commas.
Colons separating key and value pairs enhance readability in my book, so KDL goes too far for me. Other options are JSON5 (https://json5.org/) and CUE (https://cuelang.org/docs/introduction/). The latter is maximalist rather than minimalist, but very well thought out and worth checking out.