I was using it in the sense of definition 1b, a propensity or natural tendency usually other than rational: https://www.merriam-webster.com/dictionary/impulse h

I was using it in the sense of definition 1b, a propensity or natural tendency usually other than rational: https://www.merriam-webster.com/dictionary/impulse https://www.merriam-webster.com/dictionary/impulse People have liked colorizing photographs for a long time, it's a natural tendency even though it may or may not be rational.