According to an article in The Business Standard, Bangladesh Bank planned to introduce a new 50-taka note on 15 December 2019. The existing 50- and 10-taka notes (B351 and B349, shown below) are similar in color, leading to confusion in public transactions. The new 50-taka note (B351.5a) is reddish orange to help distinguish between the denominations. The new notes will circulate in parallel with the existing notes.
Courtesy of Mohammad Raihan.
This series of notes must be one of the poorest designs ever when it comes to color coordination. Already the 5- and 20-taka notes have been redesigned with new colors due to similarities with other denominations, and now the 50-taka note gets the same fate.