How to color border of only specific sides of Circular Container in Flutter

Question

I would like to know how only the border color can be set for specific sides of a circular container. Here's a small snip of what I'm trying to achieve:

The image above is wrapped inside a circular container whose border is blue on all sides but the top left.

The code I have written by far:

Container(
                    height: height * 0.15,
                    width: width * 0.3,
                    color: Colors.red,
                    // padding: EdgeInsets.only(
                    //     left: width * 0.02, right: width * 0.02),
                    child: Column(
                      // mainAxisAlignment: MainAxisAlignment.center,
                      // crossAxisAlignment: CrossAxisAlignment.center,
                      children: [
                        Stack(
                          children: [
                            Container(
                              width: width * 0.2,
                              height: height * 0.1,
                              decoration: BoxDecoration(
                                  color: Colors.white,
                                  borderRadius: BorderRadius.only(
                                      topLeft: Radius.circular(100),
                                      topRight: Radius.circular(100),
                                      bottomLeft: Radius.circular(100),
                                      bottomRight: Radius.circular(100))),
                            ),
                            Positioned(
                              // top: height * 0.1,
                              left: width * 0.12,
                              bottom: height * 0.001,
                              child: Container(
                                height: height * 0.04,
                                width: width * 0.08,
                                decoration: BoxDecoration(
                                    color: Color.fromRGBO(73, 72, 73, 0.4),
                                    borderRadius: BorderRadius.circular(100),
                                ),
                                child: Icon(Icons.camera_alt_rounded,
                                    color: Colors.white),
                              ),
                            )
                          ],
                        ),
                        Row(
                          children: [
                            Icon(Icons.upgrade, color: Colors.white),
                            SizedBox(
                              height: height * 0.05,
                            ),
                            Text(
                              'Upgrade Now',
                              textScaleFactor: textScale,
                              style: TextStyle(
                                  color: Colors.white,
                                  fontWeight: FontWeight.bold,
                                  fontSize: 12),
                            )
                          ],
                        )
                      ],
                    ),
                  ),

Any help will be appreciated. Please note I am open to all sorts of design suggestions beyond the code that I have written by far.