Inline Emoji selector's highlighted row text not legible

- Start typing `:thu` or any other emoji name
- The highlighted emoji row has light background/light foreground and can't be read.

<img width="381" alt="Screen Shot 2021-03-18 at 8 38 15 AM" src="https://user-images.githubusercontent.com/8808078/111627823-e0843580-87c5-11eb-922f-7825dc3f9d17.png">
