Unfortunately, I cannot find a script to change the image.
According to the code rear_view_camera.c, there is a #define "APP_MAKE_COLOR(red, green, blue)". And for an example, the white color is define as APP_COLOR_WHITE APP_MAKE_COLOR(0x1F, 0x3F, 0x1F). I think you may search any tool (e.g. from google) to convert the image file to RGB hex. And then use the APP_MAKE_COLOR(red, green, blue) to create an array of your logo image to replace the NXP logo.