change icon size

Complete sympathize with granny. You may join the appended bug report.

set the screen resolutions to a lower setting .so you change all the displays .

right click on the panel.
click properties
on "size:" enter any huge number. like 57 and the icons will increase to that number of pixels.

system - preference -appearance -at the bottom of the first page customize -controls -select high contrastinverse -then at the top of the same select color set to what will make her happy .

Thanks a lot for your answers.

I posted this question to check if I'm too stupid to find the solution or if it is a bug. A (simple) search for "size" in package (?) "indicator-applet" [1] returned "no bug found". I'm surprised that bug #359384 [2], which I got from the linked bug, wasn't found, even though it has "resize" in its title. If i search for "resize" I would have found it. Is this a launchpad bug?

The next "confusion" I've found is that the website link in the "info window" (right click on panel app > info) from both the session indicator *1 and the application indicator *2 points to "https://launchpad.net/indicator-applet". Therefore I put the question herein.
The icon I meant is the turn off symbol (circle with a vertical line on the border). So, which is the correct name for this application *1 and how do you distinguish the other one?

@greg: I thought about changing resolution before. This sounds for me like rough tuning (most of the monitors allow about 3 different resolutions), but it should be more fine tuning. Also, at some resolutions, the display isn't that sharp.
It is more a problem of size than contrast.

@marcus: Your solutions works with the notification area but not for the session and application indicator panel apps (according to the bug reports).

*1 German name: "Sitzungsanzeige", one part of it apparently called "Me Menu" (https://wiki.ubuntu.com/MeMenu)
*2 German name: "Benachrichtungsanzeige"

[1] https://bugs.launchpad.net/indicator-applet
[2] https://bugs.launchpad.net/ubuntu/+source/indicator-applet/+bug/359384

i see that the problem is really the shut down button here is something for you to look at ,
 right click the panel -add to panel - scroll down to shut down ,click it then at the bottom click add . this will give you a good sized red button that is easy to see .

 if you like just remove the old one from the panel , and move the new one where you need .

That is what the bug is about, indicator-applets don't resize when resizing the panel per pixel, the rest does.
How did I find the bug.
Inserted in search box of firefox:
ubuntu can't resize indicator-applet
http://www.answers.com/main/ntquery?s=ubuntu+can%27t+resize+indicator-applet&gwp=13

First entry 'UbuntuBugDay', open it.
ctrl+F
insert:
indicator-applet icon doesn't resize
almost at the bottom of the page the bug is displayed.

Regarding indicator-applets, they're applications (packages) with dependencies.
Which are (at the moment) not (meant to be) highly configurable.
e.g.
message applet sticks together with speaker symbol.
me-menu sticks together with session applet.
They're all connected via dbus.
It's kind of a cleanup going on regarding too many different icons, instead it'll merge all together.
Notification area will be skipped sooner than later in an upcoming release.

Reference.
https://wiki.ubuntu.com/DesktopExperienceTeam/ApplicationIndicators

(german)
http://ikhaya.ubuntuusers.de/2010/05/05/ayatana-traegt-fruechte-ueber-ubuntu-indikator-menues-und-notifyosd/
http://forum.ubuntuusers.de/topic/seltsame-anfrage-zum-entsperrend-des-schluess/#post-2283542
http://forum.ubuntuusers.de/topic/lautstaerkeregler-separat-vom-mail-icon-in-lu/

So if you remove whatever applet you better know missing related packages in order to roll back.
http://packages.ubuntu.com/search?suite=lucid&arch=any&searchon=names&keywords=indicator

But they'll change colors in the future.
http://blog.expatsinksa.com/?p=34

i found a way that some people might want to use
system - preference -appearance - customize - icons -high contrast inverse . if you remove the shut down then use add to panel and add the shut down . this will enlarge everything but the speaker + envalope