------
## 最终结论
```python
def colon_tuplex(tup, index, value):
    lst = list(tup)
    lst[index] = [value]
    return tuple(lst)

# Test cases
assert colon_tuplex(("HELLO", 5, [], True), 2, 50) == ("HELLO", 5, [50], True)
assert colon_tuplex(("HELLO", 5, [], True), 2, 100) == ("HELLO", 5, [100], True)
assert colon_tuplex(("HELLO", 5, [], True), 2, 500) == ("HELLO", 5, [500], True)
```