The actual strange thing is that you report the second cell does change, because neither of them should. There’s a minor issue and a major issue with what you’ve posted.
The minor issue is your comparisons items.HM_SZ_Heizung_Humidity.state > 60 and items.Home_Anwesenheitserkennung.state > 0. All states returned by items.itemName.state are string values, even if the item is some other item type. String comparisons are not the same as numerical comparisons because string comparisons look at each value one character at a time so “7” is greater than “60” because the character code for “7” is larger than the character code for “6”. To get the actual numerical comparison that you are looking for you need to convert the state to a number first using Number(value), Number.parseInt(value), or Number.parseFloat(value) depending on the situation. parseFloat is probably the most broadly applicable, so if you don’t know which one to choose, just use that one.
The major issue is that neither the oh-label-cell or the oh-cell that it is derived from accept a style property. The label cell does have a stateStyle property, but (as the name implies) that only applies styling to the state label itself. No other style declaration are passed on the the cells.
There is a direct, built-in way to change the background of a cell using the color property, but this is restricted to the default f7 color palette, so if you want a custom color such as #FF7276 then you need to use an indirect method.
The easiest is probably just to put an additional element in the background of the cell and set the background color of that element. If you add: