This works perfectly for me:

LibO 3.6.3.2

but I'm using Linux, going to ping Rainer to see if he'll test on Windows

Rainer: Mind testing, sorry for the CC, you're the only one I know who is actively triaging and using Windows :)

Checked with:
LO 4.0.0.0.beta2
Build ID: own W7 debug build
Windows 7 Professional SP1 64 bit

(In reply to comment #0)
> Format Paint Brush doesn't function well, it doesn't pick and paste all the
> parameters of format needed. For example, it can change the font but not the
> colour or the size, it even sometimes doesn't change the needed font. Well,
> it behaves differently at different times.

Works for me:
- font
- font style
- font size
- font color
- highlight

Doesn't work:
- removing highlight
- changing font color back to black

(In reply to comment #2)
> Checked with:
> LO 4.0.0.0.beta2
> Build ID: own W7 debug build
> Windows 7 Professional SP1 64 bit
> 
> Works for me:
> - font
> - font style
> - font size
> - font color
> - highlight
> 
> Doesn't work:
> - removing highlight
> - changing font color back to black

Ok, thanks for testing. Therefore I'll alter the title a bit to your listed not-working functions of the paint brush. I can reproduce these problems.

Following [1] I mark this bug as 'Minor Medium'

Kind regards,
Joren

[1] https://wiki.documentfoundation.org/images/0/06/Prioritizing_Bugs_Flowchart.jpg

Sorry, I'm a little late ...

bfoman's observateions are NOT completely  reproducible with "LibO  4.0.0.2 rc   -  GERMAN UI / German Locale  [Build ID: 5991f37846fc3763493029c4958b57282c2597e)]"  {tinderbox: @6, pull time 2013-01-24  07:20(?)} on German WIN7 Home Premium (64bit) with User Profile automatically created form renamed /3 User profile used by 3.6.5.2

Steps how to reproduce my results: with attached sample document:
1. in first line select word "black"  -> click 'Format Paintbrush', click on
   word "green"
   As expect characters of word "green" become black
2. UNDO
3. in first line select word "auto"  -> click 'Format Paintbrush', click on
   word "green"
   As expected, word "green" stays green, because local formatting has
   priority to "auto" character color of word "auto"

So I can't see a bug, back to NEEDINFO for this.

11. in second line select word "black"  -> click 'Format Paintbrush', click on
    word "green"
    As expect background of word "green" become black
12. UNDO
13. in second line select word "nofill"  -> click 'Format Paintbrush', click
    on word "green"
    Unexpectedly, background  if word "green" stays green

But in the second case I am not sure. Concerning character color in the picker there is distinguished exactly between "black" and "auto". Tha'ts correct because we need an auto function because often it's necessary to adapt character color to background color to keep them visible.

I something like "Auto" would be useless for character. "No fill" has to apply "No fill" what means no background highlighting and not "leave other locally selected properties".

So, if there are no different observations with other OS or LibO Version, I think the correct summary would be 
"Format Paint Brush doesn't change background highlighted text color to 'no fill'"

@bfoman:
Can you reproduce my results concerning character colot with attached sample?

Created attachment 74032 [details]
Sample Document

See comment before how to use

(In reply to comment #4)
> 3. in first line select word "auto"  -> click 'Format Paintbrush', click on
>    word "green"
>    As expected, word "green" stays green, because local formatting has
>    priority to "auto" character color of word "auto"
Oh ok, didn't know that... That explains why the color didn't change with my test :-).

> 13. in second line select word "nofill"  -> click 'Format Paintbrush', click
>     on word "green"
>     Unexpectedly, background  if word "green" stays green

I can confirm this behavior.

> 
> But in the second case I am not sure. Concerning character color in the
> picker there is distinguished exactly between "black" and "auto". Tha'ts
> correct because we need an auto function because often it's necessary to
> adapt character color to background color to keep them visible.
> 
> I something like "Auto" would be useless for character. "No fill" has to
> apply "No fill" what means no background highlighting and not "leave other
> locally selected properties".
I certainly agree with that! 
> So, if there are no different observations with other OS or LibO Version, I
> think the correct summary would be 
> "Format Paint Brush doesn't change background highlighted text color to 'no
> fill'"
Agreed; I'll set this bug on my todo list and try to keep this bug in mind (if no response from bug reporter I'll change the title)

(In reply to comment #6)
>> I
> > think the correct summary would be 
> > "Format Paint Brush doesn't change background highlighted text color to 'no
> > fill'"
> Agreed; I'll set this bug on my todo list and try to keep this bug in mind
> (if no response from bug reporter I'll change the title)

Therefore -> edit summary

I'm sorry for my silence. I reported this bug but now I can't relate to it, because I had this problem for Windows and for another distro,  while already for a long time since then I've been using linux and another distro of LibreOffice. However, thanks for paying attention on this and finding something out with that "no-fill" bug.

(In reply to Jorendc from comment #6)
> (In reply to comment #4)
> > 3. in first line select word "auto"  -> click 'Format Paintbrush', click on
> >    word "green"
> >    As expected, word "green" stays green, because local formatting has
> >    priority to "auto" character color of word "auto"
> Oh ok, didn't know that... That explains why the color didn't change with my
> test :-).

Unfortunately, I still do not understand this.  Maybe somebody can help me?  As a simple user I want to transfer a formatting with the Paintbrush function and not to think about anything like local formatting priority (which I myself do not know yet).  This is from my point of view not intuitive and could frustrate users. 
 
> > 13. in second line select word "nofill"  -> click 'Format Paintbrush', click
> >     on word "green"
> >     Unexpectedly, background  if word "green" stays green
> 
> I can confirm this behavior.

I can reproduce this issue with LO 4.4.0.3, Win 8.1.

(In reply to A (Andy) from comment #9)
> (In reply to Jorendc from comment #6)
> > (In reply to comment #4)
> > > 3. in first line select word "auto"  -> click 'Format Paintbrush', click on
> > >    word "green"
> > >    As expected, word "green" stays green, because local formatting has
> > >    priority to "auto" character color of word "auto"
> > Oh ok, didn't know that... That explains why the color didn't change with my
> > test :-).
> 
> Unfortunately, I still do not understand this.  Maybe somebody can help me? 
> As a simple user I want to transfer a formatting with the Paintbrush
> function and not to think about anything like local formatting priority
> (which I myself do not know yet).  This is from my point of view not
> intuitive and could frustrate users. 
>  
Trust me, you're not the only one. There is another related bug about local formatting taking priority over styles which I think is entirely unintuitive. If you'd like to comment on that bug suggesting that the UX teams accept the change feel free to do so. bug 83726

I confirm this in 4.3.3.2.

My guess is that the paintbrush is that attributes "inherited from styles" are not being copied, but should.

Try this other test in the same sample document:

1. Make both 'yellows' bold.

2. Click on 'nofill' and click Ctrl+B twice.

3. Use the paintbrush to copy formatting from 'auto' to 'yellow' in the first line.

4. Use the paintbrush to copy formatting from 'nofill' to 'yellow' in the second line.

Compare the results.

In the 'nofill' case, there is "regular weight" directly applied. In the 'auto' case, weight is inherited from the underlying style.

What should have happened is that in the 'auto' case, "weight:inherit" should be copied too.

(In reply to Rainer Bielefeld Retired from comment #4)
> 11. in second line select word "black"  -> click 'Format Paintbrush', click
> on
>     word "green"
>     As expect background of word "green" become black
> 12. UNDO
> 13. in second line select word "nofill"  -> click 'Format Paintbrush', click
>     on word "green"
>     Unexpectedly, background  if word "green" stays green

Still repro.

Arch Linux 64-bit
Version: 6.1.0.0.alpha0+
Build ID: e1fb3d95ac6d58b60448981e82d90621cad7fea5
CPU threads: 8; OS: Linux 4.14; UI render: default; VCL: kde4; 
Locale: fi-FI (fi_FI.UTF-8); Calc: group threaded
Built on January 7th 2018

Arch Linux 64-bit
LibreOffice 3.3.0 
OOO330m19 (Build:6)
tag libreoffice-3.3.0.4

I can still reproduce part of this bug in LibreOffice Impress 6.2.4.2 (Build ID: 1:6.2.4-0ubuntu0.18.04.1~lo1):

1) Open a new Impress document
2) Create two text fields (F2) with some text
3) Format one text field with e.g. font color red and highlight color yellow
4) Use the clone formatting and apply it to the second text field

The font color is correctly copied but the highlight color is not.

Using Style Inspector (tdf#134554) new feature in master, all paragraphs have Default Paragraph style applied, no paragraph-level DF; all the pieces of text in attachment 74032 [details] have no character styles, and some have character-level DF.

First line:

* "yellow": char color 0xffff00; char transparence 0.
* "black": char color 0x000000; char transparence 0.
* "green": char color 0x008000; char transparence 0, char back color 0xffffffff, char back transparent true, char shading value 0.
* "auto": no DF at all.

Second line (in fact, third paragraph):

* "yellow": char back color 0xffff00, char back transparent false, char shading value 0.
* "black": char back color 0x000000, char back transparent false, char shading value 0.
* "green": char back color 0x008000, char back transparent false, char shading value 0.
* "nofill": no DF at all.

Now when format paintbrush clones source formatting to destination, it doesn't remove from destinations what was absent in source - it only adds/overwrites what was *present* in source. So cloning formatting from "auto" or "nofill" is effectively a no-op, not adding and not modifying anything in destinations.

But if you make the "no fill" attribute explicit - e.g., select "nofill" and apply "No Fill" from Highlight Color tool's dropdown, then cloning the resulting formatting will work as expected, because then "nofill" would have this DF: char back color 0xffffffff, char back transparent true, char highlight 0xffffffff, char shading value 0.

See also tdf#135871.

And also see tdf#71481, which effectively is the same.

Let me mark it as a dupe to bug 71481; together with the latter, it changed after commit 259ed2e3a135a5650fd321f408382d6b1b86bcad. In steps from comment 4:

* After step 3, the green color of characters becomes auto, because the direct formatting of the characters gets cleared, matching "no direct formatting" of the source text;
* After step 13, the green background of characters becomes no fill, because the direct formatting of the characters gets cleared, matching "no direct formatting" of the source text.

*** This bug has been marked as a duplicate of bug 71481 ***