When you switch to the Color Tab, the Selection Follows Playhead feature is turned on, so the selected clip will be whatever is under the playhead.
Change your step 1 from selecting the clip to placing the playhead over it and you'll be fine.
Sorry, I should have said, the playhead is already over the clip before I select it in step 1.
Anything else I can try?
Then your original question leaves me thoroughly puzzled ... you said you select a clip ... and clarified that you have the playhead (CTI) over that clip ... go to the Color workspace ... um ... ?
I guess I need to know what you define as the "the currently selected original clip". You've totally lost me.
And by preview window, are you referring to the Program monitor ... or the little window in the Creative tab of Lumetri that is for previewing the application of Looks to the media? As that is what is normally referred to as the preview window, and it of course only shows the application of Looks to the media.
Please post a screen shot of the Color workspace.
Thanks for your replies, but for some reason it's all started to work ok now. Just to clarify, here's what I meant, sorry I'm not familiar with all the terminology just yet.
During a normal editing workspace, I'd double clicked a clip to display the raw footage as it came out of the camera. That appears on the top left (that's what I was calling the 'original' clip)
I then go to the the timeline and move the playhead over the clip I wanted to edit, I also selected that clip if it wasn't already selected. I then pressed the 'Colour' tab at the top so that I could adjust the exposure / colour of the selected clip. But the preview window at the top (taking up most of the width) showed the raw footage clip, not the one I wanted to edit.
But now, for some reason, the 'Color' workspace shows two preview windows, one on the left is the raw footage, one on the right is the selected clip on the timeline, and I can adjust the settings.
As it's all working, there's no point in providing a screenshot, but thanks again for the help.
Sounds like you had the Source monitor on the upper left ... and yes, that shows the source material.
The Program monitor shows the timeline as currently edited.
The "preview window" in the Lumetri panel's Creative tab shows the source material with the Look you've got showing in the drop-down box ... or navigated to via the left and right arrows in that window.
Doing Lumetri work, it's best to go to the Color Workspace, and have the scopes panel in the upper left and program monitor in the middle. Parade RGB,Vectorscope YUV, and Waveform (Luma or RGB) are your friends ... better than your eyes ... learn how to use them.