Issue is not reproduced. I was able to modify the shapes’ styles separately.
Tested on :
    • Operating system : Windows 8.1 Pro 64-bits.
    • LibreOffice : Version: 5.4.3.1 (x64)
      Build ID: 32c8895c6cae21571f364dbb059f419a743ee44d
      CPU threads: 4; OS: Windows 6.29; UI render: default; 
      Locale: en-US (en_US); Calc: group

However it is not reproduced on:
    • Operating system : Ubuntu 16.04.3 64-bits.
    • LibreOffice :Version: 5.4.3.1
      Build ID: 32c8895c6cae21571f364dbb059f419a743ee44d
CPU threads: 8; OS: Linux 4.4; UI render: default; VCL: gtk2; 
Locale: ja-JP (ja_JP.UTF-8); Calc: group

Sorry I had a mistake in the previous comment.

Issue is not reproduced. I was able to modify the shapes’ styles separately.
Tested on :
    • Operating system : Windows 8.1 Pro 64-bits.
    • LibreOffice : Version: 5.4.3.1 (x64)
      Build ID: 32c8895c6cae21571f364dbb059f419a743ee44d
      CPU threads: 4; OS: Windows 6.29; UI render: default; 
      Locale: en-US (en_US); Calc: group

Also on:
    • Operating system : Ubuntu 16.04.3 64-bits.
    • LibreOffice :Version: 5.4.3.1
      Build ID: 32c8895c6cae21571f364dbb059f419a743ee44d
      CPU threads: 8; OS: Linux 4.4; UI render: default; VCL: gtk2; 
      Locale: ja-JP (ja_JP.UTF-8); Calc: group

(In reply to t.tsuzuku from comment #0)
> Description:
> In Libreoffice Impress.
> select one shape and edit style, then effect all shapes in page.

Please keep in mind, that a "style" as listed in the sidebar panel "Styles" is intended to change all shapes, that have assigned this style and no own settings. If you want to change only one specific shape, do not change the "style" but use hard formatting of the properties as listed in the sidebar panel "Properties".

If this does not solve your problem, reopen the bug and please give a step-by-step description, how you "edit style".

This is my misunderstand.
I'm sorry for bothering a lot of people.
I thought style menu at right click of shape mean editing selected shape style like 'power point'.
I could edit shape by using property menu at right pane.
thank you

I was trying to check the issue again. I confirm it reproduces when applying modification through the following steps:

1- Open a new Impress documents
2- Add a line shape, and change it’s color to red for example by right click → edit style → Line tab
3- Add another line shape, you will find at the same style as the previous one
4- Change one of the lines color to blue for example also by right click → edit style → Line tab

Expected result: Only the selected shape should change color

Actual result: Both lines change colors.

Only in case modified from the side bar, it could be changed seperately.

Testing environment:
    • Operating system : Windows 8.1 Pro 64-bits.
    • LibreOffice : Version: 5.4.3.1 (x64)
      Build ID: 32c8895c6cae21571f364dbb059f419a743ee44d
      CPU threads: 4; OS: Windows 6.29; UI render: default; 
      Locale: en-US (en_US); Calc: group

Also on:
    • Operating system : Ubuntu 16.04.3 64-bits.
    • LibreOffice :Version: 5.4.3.1
      Build ID: 32c8895c6cae21571f364dbb059f419a743ee44d
      CPU threads: 8; OS: Linux 4.4; UI render: default; VCL: gtk2; 
      Locale: ja-JP (ja_JP.UTF-8); Calc: group

I cannot reproduce!

Version: 5.4.2.2 (x64)
Build ID: 22b09f6418e8c2d508a9eaf86b2399209b0990f4
CPU threads: 8; OS: Windows 6.19; UI render: default; 
Locale: en-US (en_US); Calc: group

I have tried to create a shape and tried to change its color etc but it doesn't reproduce.

(In reply to Aschalew from comment #6)
> I cannot reproduce!
> 
> Version: 5.4.2.2 (x64)
> Build ID: 22b09f6418e8c2d508a9eaf86b2399209b0990f4
> CPU threads: 8; OS: Windows 6.19; UI render: default; 
> Locale: en-US (en_US); Calc: group
> 
> I have tried to create a shape and tried to change its color etc but it
> doesn't reproduce.

we followed different steps and according the new steps mentioned in #comment 5. this issue can reproduce!

See comments #3 and #4.

BTW, PowerPoint does not have styles for shapes at all, but only direct formatting.