Entry widget caret is hard to see

[oddstream]

Checklist

• [X] I have searched the issue tracker for open issues that relate to the same feature, before opening a new one.
• [X] This issue only relates to a single feature. I will open new issues for any other features.

Is your feature request related to a problem?

In dark mode, the entry widget caret is shown as blue on a black background. That alone makes it hard to see, and is aggravated by the caret being (seemingly) only one pixel wide. Users with accessibility issues may find editing text in an entry difficult.

Is it possible to construct a solution with the existing API?

I cannot find a way of configuring the caret in the API.

Describe the solution you'd like to see.

Paint the caret the same color as the text.

Add ColorNameCaret and SizeNameCaretWidth to the custom theme.

[oddstream]

I note that the caret is painted in the "primary" color, as is the border of the currently focused entry widget.