[X337]

You can use 255 * (percentage) in calculator and convert it to hex.
Example :
If you want 30%, you can use calculator and count "255 * 0.3" and convert it into hex.

Код:

SetPlayerMarkerVisibility(playerid, 0x4C); // 30% (255 * 0.3 = 76.5 (4c))
SetPlayerMarkerVisibility(playerid, 51); // 20% (255 * 0.2 = 51)