1.第一步找到这个文件

2.将下面代码复制替换下图框中的地方
font.monospace.cpp=Fixedsys
style.cpp.32=font:Fixedsys,size:10,fore:#9CDCFE,back:#1E1E1E
style.cpp.4=font:Fixedsys,size:10,fore:#4EC9B0,back:#1E1E1E
style.cpp.10=font:Fixedsys,size:10,fore:#DCDCDC,back:#1E1E1E
style.cpp.1=font:Fixedsys,size:10,fore:#57A64A,back:#1E1E1E
style.cpp.2=font:Fixedsys,size:10,fore:#007F00,back:#1E1E1E
style.cpp.5=font:Fixedsys,size:10,fore:#007ACC,back:#1E1E1E
style.cpp.6=font:Fixedsys,size:10,fore:#FF80FF,back:#1E1E1E
style.cpp.11=font:Fixedsys,size:10,fore:#DCDCDC,back:#1E1E1E
style.cpp.9=font:Fixedsys,size:10,fore:#4EC9B0,back:#1E1E1E
style.cpp.7=font:Fixedsys,size:10,fore:#FF80FF,back:#1E1E1E
style.cpp.34=font:Fixedsys,size:10,fore:#500000,back:#007ACC
style.cpp.35=font:Fixedsys,size:10,fore:#FF0000,back:#1E1E1E
style.cpp.16=font:Fixedsys,size:10,fore:#9CDCFE,back:#1E1E1E

style.cpp.12=font:Fixedsys,size:10,fore:#FF80FF,back:#1E1E1E

3.把此代码也替换掉框选处
# vertical edge at right margin
edge.mode=0
edge.column=80


# Specification for text selection and caret line
selection.fore=#000000
selection.back=#005EB3
caret.fore=#FFFFFF
caret.back=#000000

# Color for vertical edge

edge.colour=#66FAFA

重启keil，大功告成！