Short of scaffolding, roof space is best way to go. Walking on the rafters is pretty easy @newbie25 - you could run a decent width plank of timber on too of the rafters so you have something to walk/balance on. Hope that makes sense.
I apologise for the delay in my reply. It's great to see @ProjectPete has already addressed your question.
Since you have potentially saved yourself a great deal of money by finding that you can switch the colouring, perhaps it would be wise to splurge on a handy person's cost to finish the job. If you are not confident in going into the roof space yourself, I encourage you not to risk it and employ some help.
@ProfSorry Prof, that won't work.
The colour of LED lights is determined by the type of internal LED chips when they are manufactured.
Changing the forward current will have NIL effect on the colour.
With incandescent bulbs that was true - at lower voltages the became redder, and at higher voltages became whiter.
Resistors are never a good idea - they waste energy which you are paying $$ for and they create heat which CAN be a fire hazard.
As @ProjectPete said, on late model downlights there is often a colour temperature switch, usually 3 way for Warm-Cool-Daylight illumination.
It would be ironic if @newbie25 swapped out the old lights only to find later that they were adjustable after all.