Bug located in ... ExportAnimation method. Unable to change the background colour for animations.

### 🔍 Before submitting the issue

- [x] I have searched among the existing issues
- [x] I am using a Python virtual environment

### 🐞 Description of the bug

Unable to change the background colour for animations.

`Graphics.Camera.SetFit()
animation_export_format = Ansys.Mechanical.DataModel.Enums.GraphicsAnimationExportFormat.GIF
settings_720p = Ansys.Mechanical.Graphics.AnimationExportSettings()
settings_720p.Resolution = GraphicsResolutionType.EnhancedResolution
settings_720p.Background = GraphicsBackgroundType.White
settings_720p.Width = 1280
settings_720p.Height = 720
settings_720p.CurrentGraphicsDisplay = False
EQ.ExportAnimation(path, animation_export_format, settings_720p)`

### 📝 Steps to reproduce

Nill

### 💻 Which operating system are you using?

Windows

### 📀 Which ANSYS version are you using?

251

### 🐍 Which Python version are you using?

3.10

### 📦 Installed packages

```shell
Package Version
------------------------- -----------
aiohappyeyeballs 2.6.1
aiohttp 3.13.2
aiosignal 1.4.0
ansys-api-dbu 0.3.28
ansys-api-geometry 0.4.83
ansys-api-mechanical 0.1.3
ansys-geometry-core 0.12.1
ansys-mechanical-core 0.11.36
ansys-mechanical-stubs 0.1.9
ansys-pythonnet 3.1.0rc6
ansys-tools-common 0.2.1
ansys-tools-path 0.8.1
anyio 4.11.0
appdirs 1.4.4
argon2-cffi 25.1.0
argon2-cffi-bindings 25.1.0
arrow 1.4.0
asttokens 3.0.1
async-lru 2.0.5
async-timeout 5.0.1
attrs 25.4.0
babel 2.17.0
beartype 0.22.5
beautifulsoup4 4.14.2
bleach 6.3.0
certifi 2025.11.12
cffi 2.0.0
charset-normalizer 3.4.4
click 8.3.1
clr_loader 0.2.8
cmcrameri 1.9
cmocean 4.0.3
colorama 0.4.6
colorcet 3.1.0
comm 0.2.3
contourpy 1.3.2
cycler 0.12.1
debugpy 1.8.17
decorator 5.2.1
defusedxml 0.7.1
exceptiongroup 1.3.0
executing 2.2.1
fastjsonschema 2.21.2
flexcache 0.3
flexparser 0.4
fonttools 4.60.1
fqdn 1.5.1
frozenlist 1.8.0
geomdl 5.4.0
grpcio 1.76.0
grpcio-health-checking 1.76.0
h11 0.16.0
httpcore 1.0.9
httpx 0.28.1
idna 3.11
ImageIO 2.37.2
ipykernel 7.1.0
ipython 8.37.0
ipywidgets 8.1.8
isoduration 20.11.0
jedi 0.19.2
Jinja2 3.1.6
joblib 1.5.2
json5 0.12.1
jsonpointer 3.0.0
jsonschema 4.25.1
jsonschema-specifications 2025.9.1
jupyter_client 8.6.3
jupyter_core 5.9.1
jupyter-events 0.12.0
jupyter-lsp 2.3.0
jupyter_server 2.17.0
jupyter_server_proxy 4.4.0
jupyter_server_terminals 0.5.3
jupyterlab 4.4.10
jupyterlab_pygments 0.3.0
jupyterlab_server 2.28.0
jupyterlab_widgets 3.0.16
kiwisolver 1.4.9
lark 1.3.1
markdown-it-py 4.0.0
MarkupSafe 3.0.3
matplotlib 3.10.7
matplotlib-inline 0.2.1
mdurl 0.1.2
meshio 5.3.5
mistune 3.1.4
more-itertools 10.8.0
msgpack 1.1.2
multidict 6.7.0
nbclient 0.10.2
nbconvert 7.16.6
nbformat 5.10.4
nest-asyncio 1.6.0
notebook_shim 0.2.4
numpy 2.2.6
overrides 7.7.0
packaging 25.0
pandas 2.3.3
pandocfilters 1.5.1
parso 0.8.5
pillow 12.0.0
Pint 0.24.4
pip 23.0.1
platformdirs 4.5.0
pooch 1.8.2
prometheus_client 0.23.1
prompt_toolkit 3.0.52
propcache 0.4.1
protobuf 6.33.1
psutil 7.1.3
pure_eval 0.2.3
pycparser 2.23
Pygments 2.19.2
pyparsing 3.2.5
python-dateutil 2.9.0.post0
python-json-logger 4.0.0
pytz 2025.2
pyvista 0.46.4
pywinpty 3.0.2
PyYAML 6.0.3
pyzmq 27.1.0
referencing 0.37.0
requests 2.32.5
rfc3339-validator 0.1.4
rfc3986-validator 0.1.1
rfc3987-syntax 1.1.0
rich 14.2.0
rpds-py 0.29.0
scikit-learn 1.7.2
scipy 1.15.3
scooby 0.11.0
semver 3.0.4
Send2Trash 1.8.3
setuptools 65.5.0
simpervisor 1.0.0
six 1.17.0
sniffio 1.3.1
soupsieve 2.8
stack-data 0.6.3
terminado 0.18.1
threadpoolctl 3.6.0
tinycss2 1.4.0
tomli 2.3.0
tornado 6.5.2
tqdm 4.67.1
traitlets 5.14.3
trame 3.12.0
trame-client 3.11.2
trame-common 1.0.1
trame-server 3.8.1
trame-vtk 2.10.0
trame-vuetify 3.1.0
typing_extensions 4.15.0
tzdata 2025.2
uri-template 1.3.0
urllib3 2.5.0
vtk 9.5.2
wcwidth 0.2.14
webcolors 25.10.0
webencodings 0.5.1
websocket-client 1.9.0
widgetsnbextension 4.0.15
wslink 2.5.0
yarl 1.22.0
```

Start at the ExportAnimation entry point and the AnimationExportSettings.Background assignment shown in the report. Reproduce the GIF export on Windows with the provided settings, then trace how the background value is passed through the animation export path. Done means the requested white background is reflected in the generated animation; no repository file or test is named, so locating the relevant implementation will require investigation.

Written by the indexing model from the issue text.