used to estimate the temperature gradient among cloud layers or between regions of thin and thick clouds [@Radigan2012; @Heinze2014]. @Metchev2015a find no correlation between spectral type and $A_{3.6}/A_{4.5}$ amplitude ratio. The top panel of Figure \[fig:amplitude\_ratios\] shows that the new sample of young objects are not obvious outliers in this plot. The mean $A_{3.6}/A_{4.5}$ across the L0-T0 range is $1.2\pm0.5$ for field brown dwarfs and $1.2\pm0.6$ for low-gravity objects, thus we see no difference between the two populations. The bottom two panels of Figure \[fig:amplitude\_ratios\] show ratios involving $J$-band detections. Apart from PSO J318.5$-$22 [@Biller2018], the mid-IR and $J$-band measurements were not taken simultaneously. Since variability amplitudes are known to evolve rapidly in some cases [e.g. @Apai2017], these results should be interpreted with a degree of caution. The middle panel, which shows $A_{J}/A_{3.6}$ amplitude ratio, by eye suggests that this ratio may be higher for the young population. The mean $A_{J}/A_{3.6}$ amplitude ratio is $3.3\pm1.8$ for the field dwarfs and $6.4\pm1.0$ for the low-gravity objects. While the mean amplitude ratios in this case are significantly different, more simultaneous amplitude measurements are necessary to robustly investigate this possible trend. Finally, the bottom panel shows the $A_{J}/A_{4.5}$ amplitude ratios for variable L 