Eng:Change () Effect by () (block)

The Change Effect by  block is a Looks block and a Stack block. The block changes the specified effect on its sprite by the specified amount. There are seven different effects to choose from: color, fisheye, whirl, pixelate, mosaic, brightness and ghost.

Example Uses
As this block changes an effect, it is used whenever an effect's value must be changed - some common uses are:
 * Changing the color of a graffiti can with the color effect
 * Using the fisheye effect to make a sprite look like it is in water
 * Whirling sprites with the whirl effect
 * Pixelating sprites with the pixelate effect
 * Creating the illusion of multiple sprites with the mosaic effect
 * Creating different brightness levels with the brightness effect
 * Making creatures transparent with the ghost effect

There can be multiple effects on a sprite at once - effects can be combined to produce even more brilliant effects.

Workaround
If a variable held the strength of the effect, the Change Effect by  block could be replicated with the following code:

set [wanted v] effect to ((current amount) + (increase))

However, while this is not possible in current versions of Scratch, it is in some Scratch Modifications.