The colour of the Cyrillic letters printed on the keyboard.
This colour is usually chosen so that the letters are clearly visible. This point does not affect the functionality of the keyboard, and the choice in this case depends mainly on personal preferences. However, there is also a practical point: for inexperienced users who have not mastered touch typing, it is desirable that the letters stand out as much as possible against the background of the keys.
Transparent letters are a separate case — they are used in keyboards equipped with a backlight (see below), due to which such characters, when the backlight is on, are visible even in the dark.
Volume control methodprovided in the keyboard (if such a possibility is provided at all).
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Through Fn. Adjustment using the Fn key (see above): increasing and decreasing the volume is carried out by simultaneously pressing Fn and one of the main keys of the keyboard (usually from the F1 — F12 row), The main advantage of this control is that it allows you not to overload the keyboard with additional controls — this, in turn, has a positive effect on the dimensions and cost. The disadvantage is the need to simultaneously press two keys, which is not always convenient.
— Additional keys.
Control with additional keys specially designed for working with volume. A very convenient and practical option: additional keys are usually clearly labeled, while they take up less space and are cheaper than a wheel or a touch slider (see below).
— Wheel.
Control by means of a mechanical wheel, the rotation of which up and down or left and right provides a change in volume. A fairly user-friendly option — visual, intuitive and accessible even blindly. At the same time, the wheel can take up quite a lot of space, and it significantly affects the cost of the keyboard.
— Touch slider. Management using a touch surface, the movement of a finger in one direction or another. The sensor takes up minimal space, looks neat
...and generally fits well with the overall design of the keyboard, but it is not cheap. Therefore, this option is extremely rare, mainly in high-end gaming or multimedia keyboards. 
