PictureBox makes white parts transparent itself

Question

My picturebox acts like it is .PNG file.

It makes white parts transparent.

Even penetrates "Form" and i'm able to see what's behind Form (like my desktop, files) .

But it seems normal in Form1.cs [Design].

//card properties and design
this.card.BackColor = System.Drawing.Color.Red;
this.card.BackgroundImage = ((System.Drawing.Image)(resources.GetObject("card.BackgroundImage")));
this.card.BackgroundImageLayout = System.Windows.Forms.ImageLayout.Zoom;
this.card.Location = new System.Drawing.Point(47, 92);
this.card.Name = "card";
this.card.Size = new System.Drawing.Size(103, 157);
this.card.SizeMode = System.Windows.Forms.PictureBoxSizeMode.AutoSize;
this.card.TabIndex = 2;
this.card.TabStop = false;
this.card.Visible = false;

Here is a picture of without running:

Second picture that explains what's my problem:

Answer 1

This looks like a TransparencyKey being set to Color.White . Try clearing that.