生成一个包含三个以上颜色的随机数列，并将其排序。
Possible solution:

```python
import random

# generate a list of random colors
colors = ['red', 'green', 'blue', 'yellow', 'purple', 'orange']  # add more colors if needed
num_colors = random.randint(3, len(colors))
color_list = random.sample(colors, num_colors)

# sort the list alphabetically
color_list.sort()

print(color_list)
```

Example output:

```
['blue', 'green', 'red', 'yellow']
```