The home innings fell away against spinners Jeevan Mendis and 16-year-old Hamidullah Qadri in the final session.
Nick Selman's patient 50 off 159 balls was the top score in a largely sedate home effort.
Earlier, seamer Tony Palladino claimed three wickets in quick succession to leave them struggling at 87-4 at tea.
Afghan-born Qadri, Derbyshire's youngest Championship player, bowled tightly with the pink ball under the floodlights, taking 1-16 in 15 overs - including the maiden wicket of Andrew Salter, caught at slip for nine off 75 balls.
Bizarrely, Derbyshire sent out two nightwatchmen in Tom Taylor and Palladino for the last two overs at 21:10 BST, but both men survived to continue on Wednesday.
Glamorgan batsman Nick Selman told BBC Wales Sport:
"It was good to spend time in the middle again, just getting used to that pink ball as they bowled pretty well and stuck to their lines. At the end we weren't patient enough and with our batting line-up we should have got 340 but hopefully we can come out and take some poles.
"When you're set (against the pink ball), it's easy to pick up but with the spin it's a bit tricky to pick up, especially Mendis when he was bowling wrong 'uns. It was quite easy to play during twilight and the more time you spend out there the better.
"If the (bad) weather stays away, we've got a big day and hopefully the quicks can take some poles early on and crack it open."
Derbyshire bowler Tony Palladino told BBC Radio Derby:
"It's always nice to get wickets early in your spell and it set us up a bit, we had a quiet middle session but we kept it reasonably tight and got our rewards later in the day.
"The pink ball is a lot different, it doesn't buff up as nicely with spit or when you polish it, you just give it a dry polish. It swung early but not much in the middle period so the spinners bowled a lot of overs and it was turning for them.
"(Hamidullah Qadri) bowled like John Emburey there, he did exactly what you what from a finger-spinner in the first innings, he kept it tight and hopefully he'll get his rewards second innings."

Wirral Council has said it is looking for investors to develop areas around the Woodside ferry terminal, the town centre and Hamilton Square.
It revealed the plan at MIPIM, Europe's largest property expo in Cannes.
An earlier scheme was abandoned in October as the authority sought "more ambitious" plans.
Council leader Phil Davies said there was "global interest" in the proposals.
"I can only report that I've never had so much interest in the last year or so from people who want to invest in Wirral, particularly in Birkenhead," he said.
"We've had an incredible amount of interest."
The proposal includes money for outlying areas, with plans to redevelop the Woodside waterfront and build residential accommodation with views over Liverpool also announced.
Derbyshire finished an attritional day's cricket on 2-0, 53 runs ahead after Glamorgan were dismissed for 237 just before the close.
[NEXT_CONCEPT]
A £1bn plan to regenerate Birkenhead has been unveiled, five months after a previous £30m development plan was scrapped.