Description:
Currently, LibreOffice Calc does not provide permanent color-coded (rainbow) parentheses when editing complex formulas. While it offers a brief highlight when the cursor moves past a bracket, it lacks the visual clarity provided by competing software like Microsoft Excel or Google Sheets.
In complex nested formulas (e.g., using multiple IF, LET, or VLOOKUP functions), it is extremely difficult for users to track matching pairs of parentheses visually.

Steps to Reproduce:
1.Open LibreOffice Calc.
2.Enter a nested formula like: =IF(SUM(A1:A10)>0; IF(AVERAGE(A1:A10)>5; "High"; "Low"); "Zero")
3.Click inside the formula bar to edit.

Actual Results:
All parentheses are the same color (usually black). There is only a temporary bold/flash effect when the cursor is next to a bracket.

Expected Results:
Each nested pair of parentheses should have a distinct, consistent color (e.g., 1st level: Red, 2nd level: Green, 3rd level: Blue) to improve readability and reduce syntax errors.


Reproducible: Always


User Profile Reset: Yes

Additional Info:
This feature is crucial for professional users who handle large, complex formulas. It would significantly improve the UX and accessibility of Calc.

Version: 25.8.4.2 (X86_64) / LibreOffice Community
Build ID: 580(Build:2)
CPU threads: 16; OS: Linux 6.14; UI render: default; VCL: gtk3
Locale: el-GR (en_US.UTF-8); UI: en-US
Ubuntu package version: 4:25.8.4~rc2-0ubuntu0.24.04.1~lo1
Calc: threaded