  We present the results of our optical (VRI) observations of the TeV blazar PG
1553+113 over eight nights in 2016 April. We monitored the blazar
quasi-simultaneously in V and R bands each night and examined the light curves
(LCs) for intraday flux and color variations using two of the most powerful
tests; the power-enhanced F-test and the nested ANOVA test. The source was
found to be significantly (> 99%) variable in both V and R bands only on April
13, while clear variations only in R band LCs were seen on April 8 and 12. No
temporal variation was seen in the color during the observation period. We did
not find any significant correlation between V-R color index and R magnitude on
any observing night. We found a mean optical spectral index of $\sim 0.83 \pm
0.02 $ with a maximum variation of 0.21 by fitting a power law ($F_{\nu}
\propto \nu^{-\alpha}$) in the optical (VRI) spectral energy distribution of PG
1553+113. We briefly discuss the possible physical processes responsible for
the observed flux and spectral variability.
