Why my display went black

While charging my display background went black. How to reset to original blue color?

After the purchase, without special settings, watch face background was in nice blue color, text in white color. Now, all of the sudden color is black (text in white color). I prefer the original blue color but I do not know how to set it back to blue. I have tried all the available settings, none of them is related to display color. I also tried reset to factory settings, it did not help. Version of the firmware DM09_V3_C_151013, released 2015.10.13. Please, advise. Thanks, Misha