You might try the California forum - lots of So Cal folks there. You also might want to consider using some containers. Those palm roots are pretty dense and it's almost impossible to plant anything in their root zone.

I am going to give you tropical suggestions, instead of the lookalikes we use here in NC.

Hibiscus Rosa-Sinesis 'Burnished Gold'

Hibiscus Rosa-Sinesis 'Snow Queen'

Gardenia Jasminoides 'August Beauty'

http://www.fancyhibiscus.com/

Logan none of that is going to grow in palm tree roots.

Someone suggested a couple of combinations(Coral Bells two different varieties),(Mexican heather,Lantana,Variegated Flax Lily),(Azalea,foxtail fern,Astilbes).I am not sure all those combinations should survive or not)

You pretty much need a chain saw to get through those roots and they'll just grow back with vigor! A large, low container filled with blooming annuals appropriate for your zone and site will give you color. Since you are in So Ca you can change the plants out 2-3 times per year and have something blooming year round.