Some properties are not applyed at "Edit Bar Title"

**Env:** OS is Sisyphus-KWorkstation-10.1-x86-64 with KDE Frameworks 5.107.0

**Product Version:** Mayavi-4.8.1

**Steps to reproduce:**

1. Launch Mayavi
2. File -> Run python script -> Open boy.py (attached)
3. Colors and Legends -> Show Legend -> Edit bar Title
4. Check "Frame" box and choose another background color

**Expected result:**
Frame has appeared around the Title. Background has become purple.

**Observed result:**
Little white striped appear upper the 1,00, but frame is not applyed. The background has stayed the same as it did before.


[boy.py.docx](https://github.com/enthought/mayavi/files/12015894/boy.py.docx)