What MCU/Processor/Board and compiler are you using?
stm32f429
What LVGL version are you using?
v8
What do you want to achieve?
when the active tab is selected the blue part appears on the active tab.
I show the blue part in the bottom image.
1- how can change the color?
2- how can remove it?
Screenshot and/or video
If possible, add screenshots and/or videos about the current state.
The trick is to pass lv.PARTS.ITEMS and lv.STATE.CHECKED to tabview.set_style_....() function.
You can call any .set_style_...() function of the tabview object with those 2 “selectors”, and style will be applied to them.
Example (MicroPython): tab_btns.set_style_bg_color(lv.color_white(), lv.PART.ITEMS | lv.STATE.CHECKED)
In that you are correct, that the LV_PART_ITEMS selector is missing from the lv_tabviewdocumentation, but the tab buttons is a lv_btnmatrix, which has this selector, so we indirectly refer to buttons as “items”.
The example (from LVGL docs) contains the lv.PART.ITEMS and lv.STATE.CHECKED selectors also: