Color Picker doesn't open if alpha value in rgba() starts with .

1. Load the following HTML:

```
<html>
    <body>
        <h1 style="color: rgba(0, 0, 0, .4);">Hello</h1>
    </body>
</html>
```
1. Put the cursor anywhere in the `rgba()` value
2. Ctrl-E

Results:
Color picker doesn't open

Expected:
Color picker

Note: If you change the alpha value from `.4` to `0.4` everything works.
