Fix color bug in clear() method

[manele-se]

The green and blue components of the background were switched in the clear() method.

[github-actions]

Memory usage change @ b2168e6

Board	flash	%	RAM for global variables	%
arduino:samd:arduino_zero_edbg	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkrzero	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:nano_33_iot	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0

Click for full report table

Board	examples/ASCIIDraw flash	%	examples/ASCIIDraw RAM for global variables	%
arduino:samd:arduino_zero_edbg	0	0.0	0	0.0
arduino:samd:mkrzero	0	0.0	0	0.0
arduino:samd:nano_33_iot	0	0.0	0	0.0

Click for full report CSV

Board,examples/ASCIIDraw<br>flash,%,examples/ASCIIDraw<br>RAM for global variables,%
arduino:samd:arduino_zero_edbg,0,0.0,0,0.0
arduino:samd:mkrzero,0,0.0,0,0.0
arduino:samd:nano_33_iot,0,0.0,0,0.0

[per1234]

Thanks so much for the fix @manele-se!