Peter King says the exact opposite - that the Colts won't trade the 4th pick for LJ. He says the Ravens would, the Colts wouldn't.
"That brings us to Lamar Jackson. After Jackson tweeted last week that he’d asked to be traded, there was speculation the Colts would be interested, in part because of the desperation of owner Jim Irsay. And if the guarantees weren’t stupid, I think the Colts would be interested. My bet is the Ravens would take the fourth pick in the draft, solely, for Jackson. But I can’t see the Colts getting involved with Jackson having the injury history of the last two years (34 percent of the Ravens’ offensive snaps missed in ’21 and ’22, with Jackson starting and finishing one of Baltimore’s 12 December/January games in the last two years) and wanting a fully guaranteed contract. Rampant speculation, some fueled by Jackson, is that Baltimore has offered a three-year pact fully guaranteed and it wasn’t good enough."
https://profootballtalk.nbcsports.com/2023/04/03/nfl-draft-carolina-panthers-bryce-young-peter-king-fmia/?cid=fmiatw