Some people accept the term, others do not.

I'm going to be completely honest - I have no idea what other word can be used in its place to convey what it means in this context.

The intended audience will know that your post didn't intend to offend IMO

I have never heard it used as a racist word, I don't think you need to worry

you're fine, dude. no idea what the other person is talking about.

"ricing" in this context means heavily modifying the layout, theme and usability of the desktop environment.

It's a term used in the Linux community and I believe it originally comes from the automotive tuning community, particularly the JDM (Japanese domestic market) subscene.

English is my first language and I've never heard of another meaning for rice apart from the food.

It comes from making fun of Asian cars/motor-cycles after ww2.

Then it was to refer to modified Asian cars in the 2000's, mostly in a negative way. These are the cars that are painted bright colours, have under-glow lighting, decals, full body-kits, and spoilers that are larger than they need to be. Look up the race "Street racing Syndicate" for examples.

It then came to the PC community, where it was used for fully customized rigs or UIs.
People in this group may have never heard it being used in a racist way, especially if they are under 30, and they may not mean any harm by using it.

It comes from making fun of Asian cars/motor-cycles after ww2.

Then it was to refer to modified Asian cars in the 2000’s, mostly in a negative way. These are the cars that are painted bright colours, have under-glow lighting, decals, full body-kits, and spoilers that are larger than they need to be. Look up the race “Street racing Syndicate” for examples.

It then came to the PC community, where it was used for fully customized rigs or UIs. People in this group may have never heard it being used in a racist way, especially if they are under 30, and they may not mean any harm by using it.