Repository: stable-diffusion-webui
Issue: [Bug]: Emphasis being applied outside of parentheses by `:3` and `:0` (even with emphasis disabled)
Labels: bug-report

### Checklist

- [X] The issue exists after disabling all extensions
- [X] The issue exists on a clean installation of webui
- [ ] The issue is caused by an extension, but I believe it is caused by a bug in the webui
- [X] The issue exists in the current version of the webui
- [X] The issue has not been reported before recently
- [ ] The issue has been reported before but has not been fixed yet

### What happened?

Emoticons like `:3` and `:0` are being treated as emphasis despite being outside of any parentheses and even when emphasis is completely disabled. I'm able to escape the number after the colon to avoid the issue (`:\3`) but clearly something is wrong with the way emphasis is handled.

Using `:99` makes the problem more obvious. It seems to be emphasizing everything before the colon.

![image](https://github.com/AUTOMATIC1111/stable-diffusion-webui/assets/114889020/bdf98383-09f5-48be-9e6d-be2187870c25)

```
zero pictured, mountain, forest, rock, detailed background, sky, cloud, :99
Steps: 20, Sampler: DPM++ 2M, Schedule type: Karras, CFG scale: 7, Seed: 3356435071, Size: 512x512, Model hash: 591402ba62, Model: Fluffyrock-Unleashed-v1-0, VAE hash: 235745af8d, VAE: furception_vae_1-0.safetensors, Noise Schedule: Zero Terminal SNR, Version: v1.9.3-3-g43712d42
```

Same prompt but with escaped `:99 -> :\99`
![image](https://github.com/AUTOMATIC1111/stable-diffusion-webui/assets/114889020/6b1d7712-67b1-4405-935e-743b12bfd430)


### Steps to reproduce the problem

1. Append `:99` to any prompt, outside of parentheses.
2. Generated image is fried due to high emphasis

### What should have happened?

`:3` and similar should be treated as literal strings outside of parentheses

### What browsers do you use to access the UI ?

Mozilla Firefox

### Sysinfo

[sysinfo-2024-05-13-00-03.json](https://github.com/AUTOMATIC1111/stable-diffusion-webui/files/15288009/sysinfo-2024-05-13-00-03.json)


### Console logs

```Shell
################################################################
Install script for stable-diffusion + Web UI
Tested on Debian 11 (Bullseye), Fedora 34+ and openSUSE Leap 15.4 or newer.
################################################################

################################################################
Running on hope user
################################################################

################################################################
Repo already cloned, using it as install directory
################################################################

################################################################
python venv already activate or run without venv: /home/hope/src/sd/stable-diffusion-webui/venv
################################################################

################################################################
Launching launch.py...
################################################################
glibc version is 2.39
Check TCMalloc: libtcmalloc_minimal.so.4
libtcmalloc_minimal.so.4 is linked with libc.so,execute LD_PRELOAD=/usr/lib/libtcmalloc_minimal.so.4
Python 3.11.9 (main, Apr 30 2024, 07:54:26) [GCC 13.2.1 20240417]
Version: v1.9.3-3-g43712d42
Commit hash: 43712d42570c4de09224f43bc2b56cfd59081844
Launching Web UI with arguments: --api --flash-attn
no module 'xformers'. Processing without...
no module 'xformers'. Processing without...
No module 'xformers'. Proceeding without it.
*** "Disable all extensions" option was set, will not load any extensions ***
Loading weights [591402ba62] from /home/hope/src/sd/stable-diffusion-webui/models/Stable-diffusion/Fluffyrock-Unleashed-v1-0.safetensors
Running on local URL:  http://127.0.0.1:7860

To create a public link, set `share=True` in `launch()`.
Startup time: 5.9s (prepare environment: 1.1s, import torch: 2.7s, import gradio: 0.5s, setup paths: 0.7s, other imports: 0.3s, create ui: 0.3s).
Creating model from config: /home/hope/src/sd/stable-diffusion-webui/models/Stable-diffusion/Fluffyrock-Unleashed-v1-0.yaml
Loading VAE weights from user metadata: /home/hope/src/sd/stable-diffusion-webui/models/VAE/furception_vae_1-0.safetensors
Applying attention optimization: flash_attn... done.
Textual inversion embeddings loaded(2): boring_e621_fluffyrock_v4, detailed_e621
Textual inversion embeddings skipped(3): feffyxl1, feffyxl2, feffyxl3
Model loaded in 2.2s (load weights from disk: 0.5s, create model: 0.2s, apply weights to model: 1.0s, calculate empty prompt: 0.2s).
100%|███████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████| 20/20 [00:01<00:00, 19.81it/s]
Total progress: 100%|███████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████| 20/20 [00:01<00:00, 19.34it/s]
Total progress: 100%|███████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████| 20/20 [00:01<00:00, 21.17it/s]
```


### Additional information

_No response_