Why wavelength of Rubidium flame test(red violet) is more than Lithium(crimson red)

My teacher show this table from my book
[![enter image description here](https://i.stack.imgur.com/t89Zu.jpg)](https://i.stack.imgur.com/t89Zu.jpg)


Here, you can see Red violet wavelength is more than Lithium, which is against order of visible light which increase according to acronym 'VIBGYOR'


According to it violet has lesser wavelength than red(or it's shades)


**what is the basic reason?**


