For changing indicator's properties click left mouse button on the indicator's mark (in left part of the frame) and select
"Properties .." in the shortcut menu.
There will be different properties windows because of different sets of indicator's parameters and lines.
For example for Stochastic oscillator you will see the following window:
User can change here color, thickness and style of each line as well as indicator's parameters and oversold, overbought and central line values.
SetActive item in this shortcut menu makes indicator visible in the case when indicator was present at the cart, but was not visible because of variance of it's vertical scale with scales of other indicators. Selecting this item in the shortcut menu makes indicator active and visible.
Delete item in this shortcut menu deletes current indicator.