Question: Plotting using 'filled' between parallel lines without losing gridlines

Good day,

I have plotted a family of lines in one graph, and now I want to shade an area between two horizontal (parallel) lines, for example 2 and 5.
So what I did was to use the command 'filled'. First I shaded the area in vertical direction from 0 to 2 white. After that I filled the area in vertical direction from 0 to 5 for example blue.
This results in a shaded area between 2 and 5 in the color blue, what I like to have.

Question: Is there a way (a command) to fill an area between two horizontal lines more easily? So that I shade it between 2 and 5 in just one commandline. Now I first make a part white, and then the next 'layer' behind is in the color I'd like to have.

Another thing is that when I shade an area in the color white, my gridlines disappear! Is there a way to avoid this?

I have found information about shading area between two intersecting lines (can be done relatively easy), but between two horizontal (parallel) lines I still can't find a simpler way to do it.

Somebody got a suggestion?

Greetings,
Frank