Adobe Premiere Elements 11, Clip looks negative

Videomerge is a simplified version of Chroma Key. 

Look about 3:55 into my Chroma Key tutorial.

Used Mediainfo on the clip:

General
Complete name : F:\video editing\Hamm Farewell\VID-20200707-WA0000.mp4
Format : MPEG-4
Format profile : Base Media / Version 2
Codec ID : mp42 (isom/mp41/mp42)
File size : 5.16 MiB
Duration : 27 s 500 ms
Overall bit rate : 1 575 kb/s
Encoded date : UTC 2020-04-18 07:21:44
Tagged date : UTC 2020-04-18 07:21:47

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Baseline@L3.1
Format settings : 1 Ref Frames
Format settings, CABAC : No
Format settings, Reference frames : 1 frame
Format settings, GOP : M=1, N=15
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 27 s 500 ms
Bit rate : 1 509 kb/s
Width : 848 pixels
Height : 480 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 30.000 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.124
Stream size : 4.95 MiB (96%)
Title : Core Media Video
Encoded date : UTC 2020-04-18 07:21:44
Tagged date : UTC 2020-04-18 07:21:47
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Codec configuration box : avcC

Audio
ID : 2
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 27 s 500 ms
Source duration : 27 s 562 ms
Bit rate mode : Constant
Bit rate : 64.0 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 44.1 kHz
Frame rate : 43.066 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 210 KiB (4%)
Source stream size : 210 KiB (4%)
Title : Core Media Audio
Encoded date : UTC 2020-04-18 07:21:44
Tagged date : UTC 2020-04-18 07:21:47