See, with Calc it's super easy to do conditional formatting. You choose the cells, use the right reference, then simply apply a formatting to all affected cells by creating a new style by selecting "new style," then navigating through a popup with 8 tabs and a few dozen options and thinking hard about why that box says "default," like is this the default? Are you basing your style on the default? Why? Give your new style a name, select all the options that apply for formatting, and five minutes later, voila! You now have a style that you can use forever! Unless you got something wrong. Except you can't ever use it in a new sheet, unless you go through the multi-step process documented somewhere in the documents (but way easier to just search reddit) for creating a new template and then basing future documents on that template.
What if you just want the background of cells that have values over 4 to be yellow? Same process!
I love your entire concept, #LibreOffice, but gods your shit is ridiculously complicated sometimes.
p.s. I'm ranting about usability of a #foss software package. If you are coming to say "So you would prefer to use CoMmeRCiAl CoRPoRAtE SoFTwARe?" please reconsider.