New histogram chart implemented in 25.2 by 07ae0e5ada7cb595eb4815413a5bdd442c32a6ab for bug 82716 doesn't use the default blue that other charts use (e.g. simple one-series bar chart), the first colour used in the palette in Tools > Options > Chart > Default colours. Tested in own build with patch.
Created attachment 195927 [details] Restored Default color of histogram chart I think this is resolved by my mentor Tomaz (quikee) in the following PR - https://gerrit.libreoffice.org/c/core/+/171952/2