the red parts are differet with blue parts obviously as the second photo showing
![](/resized-image/__size/320x240/__key/communityserver-discussions-components-files/151/7245.jpg)
![](/resized-image/__size/320x240/__key/communityserver-discussions-components-files/151/pastedimage1637205024175v2.png)
![](/resized-image/__size/320x240/__key/communityserver-discussions-components-files/151/SN74LS377.png)
![](/resized-image/__size/320x240/__key/communityserver-discussions-components-files/151/QQ_FE564772_20211118111906.png)
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This is not oxidation. Most devices in DIP packages have roughened leadframes; see [FAQ] Why do the leadframes look strongly oxidized or corroded?
Apparently, you got chips from two manufacturing runs with different amounts of acid roughening.