How can I keep the keyboard backlit in one color?

You can press FN+2 to make it just freeze on one color at a time.

Will the distance between the keyboard itself or the keycaps be very large?

The size of the keyboard is the same as that of an ordinary keyboard, and the distance between the keycaps is evenly distributed. When you change to a brand-new keyboard, you need to get used to it slowly.

Can this keyboard read clearly when using it at night?

Yes, if you turn on the backlight in a dark room, you can still see the font clearly and type easily, and you can adjust the brightness to the brightness you think is appropriate.

How long can the keyboard light last, and will it turn off when not in use?

If you want to turn off the backlight , you need to turn off the computer, put the computer to sleep, or press FN+PrtSc on the keyboard to choose to turn off the light.

How big are the keyboard fonts?

The keyboard is about four times larger than normal fonts.