This is the 7817th most frequent Russian word.
кб
The Russian word "кб" is an abbreviation that can mean "килобайт" (kilobyte) in English, referring to a unit of digital information storage.
In this sentence, 'кб' denotes kilobytes, which is a unit of digital information storage.
Файл с фотографиями весит всего 500 кб.
The file with photos weighs only 500 kB.
Here, 'кб' refers, metaphorically, to a measure of data related to color depth, even though it might not be technically standard.
На картинке глубина цвета составляет 2 кб.
In the image, the color depth is 2 kB.
In this instance, 'кб' is used to specify a required amount of free digital storage for an action.